SOC attack detection and response rules for Splunk SIEM with MITRE ATT&CK mapping, investigation queries, and incident response playbooks

---

Overview

Security Operation Center (SOC) attack detection and response rules for Splunk SIEM. Each rule includes comprehensive SPL queries, MITRE ATT&CK mapping, false positive tuning guidance, investigation queries, and incident response playbooks.

• 170+ detection rules across Windows AD, RHEL Linux, Apache Web Server, and recent threat campaigns
• MITRE ATT&CK mapped -- every rule tagged with technique IDs and tactics
• Investigation queries -- ready-to-run SPL for SOC analyst triage
• Incident response playbooks -- step-by-step response procedures per attack type

---

Repository Structure

Detection-Engineering/
├── README.md
├── docs/
│   └── banner.svg
└── splunk_rules/
    ├── credential_access/
    │   ├── adcs_attack_detection.yml
    │   ├── dcsync_attack_detection.yml
    │   ├── golden_ticket_attack_detection.yml
    │   ├── gpo_modification_detection.yml
    │   ├── kerberoasting_attack_detection.yml
    │   ├── lsass_credential_dumping_detection.yml
    │   ├── ntds_dit_extraction_detection.yml
    │   ├── pass_the_hash_detection.yml
    │   ├── password_spraying_detection.yml
    │   └── privileged_group_membership_modification_detection.yml
    ├── apache_webserver/
    │   ├── apache_path_traversal_detection.yml
    │   ├── apache_web_shell_detection.yml
    │   ├── apache_sqli_xss_detection.yml
    │   ├── apache_brute_force_dos_detection.yml
    │   ├── apache_reconnaissance_detection.yml
    │   └── apache_exploitation_detection.yml
    ├── recent_attacks/
    │   └── cve_2026_21509_apt28_operation_neusploit_detection.yml
    └── rhel_linux/
        ├── rhel_privilege_escalation_detection.yml
        ├── rhel_persistence_detection.yml
        ├── rhel_credential_access_detection.yml
        ├── rhel_defense_evasion_detection.yml
        ├── rhel_execution_detection.yml
        ├── rhel_lateral_movement_detection.yml
        ├── rhel_discovery_enumeration_detection.yml
        └── rhel_exfiltration_detection.yml

Detection Rules — Windows Active Directory

Rule File	Attack Technique	MITRE ID	Severity	Detection Vectors
adcs_attack_detection.yml	ADCS Certificate Abuse (ESC1-ESC13)	T1649	CRITICAL	9 rules + 5 investigation queries
dcsync_attack_detection.yml	DCSync Credential Dumping	T1003.006	CRITICAL	5 rules + 4 investigation queries
golden_ticket_attack_detection.yml	Golden Ticket Kerberos Forgery	T1558.001	CRITICAL	6 rules + 8 investigation queries
gpo_modification_detection.yml	GPO Modification / Domain Policy Abuse	T1484.001	CRITICAL	7 rules + 8 investigation queries
kerberoasting_attack_detection.yml	Kerberoasting + AS-REP Roasting	T1558.003, T1558.004	CRITICAL	7 rules + 5 investigation queries
lsass_credential_dumping_detection.yml	LSASS Memory Credential Dumping	T1003.001	CRITICAL	7 rules + 5 investigation queries
ntds_dit_extraction_detection.yml	NTDS.dit Database Extraction	T1003.003	CRITICAL	8 rules + 8 investigation queries
pass_the_hash_detection.yml	Pass-the-Hash Lateral Movement	T1550.002	CRITICAL	6 rules + 5 investigation queries
password_spraying_detection.yml	Password Spraying + Brute Force	T1110.003, T1110.001	HIGH–CRITICAL	7 rules + 4 investigation queries
privileged_group_membership_modification_detection.yml	Privileged AD Group Modification	T1098.001	CRITICAL	6 rules + 7 investigation queries

Rule Format

Each detection rule file (YAML) includes:

• Rule metadata — name, description, MITRE ATT&CK mapping, confidence, risk score
• Splunk SPL query — ready-to-deploy correlation search
• Schedule configuration — cron, time window, throttle settings
• Splunk ES actions — notable event creation, risk scoring
• False positive guidance — known FPs and tuning instructions
• Investigation queries — manual IR queries for deeper analysis
• Response playbook — step-by-step incident response procedure

---

DCSync Attack Detection

File: splunk_rules/credential_access/dcsync_attack_detection.yml

Detects DCSync credential dumping (MITRE T1003.006) through 5 complementary detection rules:

Rule	Detection Method	Event IDs	Confidence
Rule 1	User account performing replication	4662 + 4624	HIGH
Rule 2	Replication from non-DC source IP	4662 + 4624 + DC lookup	HIGH
Rule 3	Replication permissions granted	5136	HIGH
Rule 4	Bulk replication burst (volume anomaly)	4662	MEDIUM-HIGH
Rule 5	DRSUAPI network traffic from non-DC	Network Traffic model	HIGH

Prerequisites

1. Audit Policy — Enable "Audit Directory Service Access" (Success) on all DCs
2. SACL — Configure auditing on domain root for replication extended rights
3. Log Forwarding — Splunk Universal Forwarder on all DCs forwarding Security logs
4. DC IP Lookup — dc_ip_list.csv for Rules 2 and 5

Quick Deploy

1. Copy the SPL query from Rule 1 into Splunk > Search & Reporting
2. Replace YOURDC01$, YOURDC02$ with your actual DC machine account names
3. Add any Azure AD Connect service accounts (MSOL_*) to the exclusion list
4. Save as a scheduled search or Splunk ES correlation search
5. Test with a 24-hour lookback to verify baseline before enabling alerts

---

ADCS Attack Detection

File: splunk_rules/credential_access/adcs_attack_detection.yml

Detects Active Directory Certificate Services abuse (MITRE T1649) through 9 complementary detection rules covering ESC1 through ESC13:

Rule	Detection Method	Event IDs	ESC Variant	Confidence
Rule 1	Certificate issued with SAN mismatch	4887	ESC1	HIGH
Rule 2	Suspicious PKINIT certificate authentication	4768	ESC1/ESC3	HIGH
Rule 3	Certificate template modification	5136	ESC4	HIGH
Rule 4	EDITF_ATTRIBUTESUBJECTALTNAME2 flag	4688, 4104, 4657	ESC6	CRITICAL
Rule 5	Machine PKINIT from unexpected IP	4768	ESC8	HIGH
Rule 6	Vulnerable template detection (daily audit)	4898	ESC2/ESC3	MEDIUM
Rule 7	ADCS attack tool detection	4688, 4104	All	HIGH
Rule 8	OID group link modification	5136	ESC13	HIGH
Rule 9	CA configuration change	4890, 4876	ESC5/ESC7	MEDIUM-HIGH

Prerequisites

1. Audit Policy — Enable "Audit Certification Services" (Success + Failure) on all CAs
2. Audit Policy — Enable "Audit Directory Service Changes" (Success) on all DCs
3. Log Forwarding — Splunk Universal Forwarder on all CAs and DCs forwarding Security logs
4. Machine IP Lookup — machine_ip_list.csv for Rule 5 (machine account to expected IP mapping)
5. Certificate Template Auditing — Enable object access auditing on certificate template objects in AD

Quick Deploy

1. Copy the SPL query from Rule 1 into Splunk > Search & Reporting
2. Replace YOUR-CA-01 with your actual CA server hostname
3. Add legitimate enrollment service accounts to the exclusion list
4. Save as a scheduled search or Splunk ES correlation search
5. Test with a 7-day lookback to establish a baseline of normal certificate issuance
6. Deploy Rules 6 and 9 first (lower noise) before enabling the higher-fidelity rules

---

Kerberoasting Attack Detection

File: splunk_rules/credential_access/kerberoasting_attack_detection.yml

Detects Kerberoasting (MITRE T1558.003) and AS-REP Roasting (MITRE T1558.004) through 7 complementary detection rules:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	RC4 encryption downgrade in TGS request	4769	T1558.003	HIGH
Rule 2	Bulk TGS requests — volume anomaly (spray)	4769	T1558.003	HIGH
Rule 3	Privileged service account targeted (adminCount=1)	4769	T1558.003	HIGH
Rule 4	AS-REP Roasting — pre-auth disabled account	4768	T1558.004	HIGH
Rule 5	Kerberoasting tool execution (Rubeus, Invoke-Kerberoast, Impacket)	4688, 4104	T1558.003/004	HIGH
Rule 6	RC4 TGS from external or non-standard source	4769	T1558.003	HIGH
Rule 7	SPN enumeration precursor — LDAP/PowerShell	1644, 4688, 4104	T1087.002	MEDIUM

Prerequisites

1. Audit Policy — Enable "Audit Kerberos Service Ticket Operations" (Success + Failure) on all DCs
2. Audit Policy — Enable "Audit Kerberos Authentication Service" (Success + Failure) on all DCs
3. Command-Line Logging — Enable process creation with command-line logging via GPO on all endpoints
4. PowerShell Logging — Enable Script Block Logging via GPO on all endpoints
5. Log Forwarding — Splunk Universal Forwarder on all DCs and endpoints forwarding Security + PowerShell logs
6. Privileged SPN Lookup — privileged_spn_accounts.csv in Splunk for Rule 3 (scheduled AD export)

Quick Deploy

1. Start with Rule 1 (RC4 downgrade) — highest-confidence, lowest noise in AES-enforced environments
2. Baseline your environment for legitimate RC4 consumers before enabling (run as report for 14 days first)
3. Build the privileged_spn_accounts.csv lookup from AD (adminCount=1 + servicePrincipalName set)
4. Deploy Rule 4 (AS-REP Roasting) immediately — PreAuthType=0 should never occur in hardened AD
5. Deploy Rule 5 (tool detection) immediately — zero expected false positives from legitimate tooling
6. Tune Rule 2 volume threshold (default 10 SPNs/15 min) using your environment baseline

---

LSASS Credential Dumping Detection

File: splunk_rules/credential_access/lsass_credential_dumping_detection.yml

Detects OS credential dumping via LSASS process memory (MITRE T1003.001) through 7 complementary detection rules covering Mimikatz, Sysinternals ProcDump, comsvcs.dll MiniDump (LOLBAS), Task Manager dumps, WerFault abuse, and SSP/DLL injection:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	Sysmon ProcessAccess to lsass.exe — suspicious GrantedAccess bitmask	Sysmon 10	T1003.001	HIGH
Rule 2	LSASS memory dump file created in suspicious path	Sysmon 11	T1003.001	HIGH
Rule 3	Mimikatz binary, CLI syntax, or Invoke-Mimikatz detected	4688, Sysmon 1, 4104	T1003.001	HIGH
Rule 4	ProcDump / comsvcs.dll MiniDump / createdump / WerFault targeting LSASS	4688, Sysmon 1	T1003.001, T1218.011	HIGH
Rule 5	Unsigned or unexpected DLL loaded into lsass.exe process space	Sysmon 7	T1003.001, T1547.005	MEDIUM-HIGH
Rule 6	WDigest UseLogonCredential registry key enabled — plaintext credential staging	Sysmon 13, 4657	T1003.001, T1112	HIGH
Rule 7	SeDebugPrivilege acquired by non-system process — Mimikatz precursor	4703	T1134.001	MEDIUM

Prerequisites

1. Sysmon Deployment — Deploy Sysmon with LSASS ProcessAccess (Event 10), FileCreate for .dmp (Event 11), ImageLoad into lsass.exe (Event 7), and RegistryValueSet (Event 13) rules enabled
2. Audit Policy — Enable "Audit Process Creation" (Success) with command-line logging on all endpoints
3. PowerShell Logging — Enable Script Block Logging via GPO on all endpoints
4. Audit Token Rights — Enable "Audit Token Right Adjusted" (Event 4703) for Rule 7
5. Log Forwarding — Splunk Universal Forwarder on all endpoints forwarding Security + Sysmon + PowerShell logs
6. LSASS Allowlist — Build lsass_access_allowlist.csv with known-legitimate processes (EDR/AV agents, Windows system processes)

Quick Deploy

1. Deploy Rule 3 (Mimikatz CLI syntax) and Rule 4 (ProcDump/comsvcs.dll) first — zero noise, immediate value
2. Deploy Rule 6 (WDigest enable) immediately — no false positives, and gives advance warning before dumping occurs
3. Deploy Rule 2 (dump file creation) next — low noise, catches the output artifact regardless of tool used
4. Build your lsass_access_allowlist.csv by monitoring Rule 1 (Sysmon Event 10) in report mode for 7 days to identify legitimate LSASS callers in your environment
5. Enable Rule 1 (GrantedAccess) after allowlist is built — highest fidelity, requires tuning
6. Enable LSASS PPL (RunAsPPL=1) and Credential Guard to reduce attack surface while detection is being tuned

---

Pass-the-Hash Detection

File: splunk_rules/credential_access/pass_the_hash_detection.yml

Detects Pass-the-Hash lateral movement (MITRE T1550.002) through 6 complementary detection rules covering classic NTLM hash replay, Mimikatz sekurlsa::pth, Overpass-the-Hash, Impacket tool signatures, and chained TTP correlation with LSASS dumps:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	Classic PtH — NTLM Type 3, null subject SID, KeyLength=0	4624	T1550.002	HIGH
Rule 2	Mimikatz sekurlsa::pth — LogonType 9 + seclogo process	4624	T1550.002	HIGH
Rule 3	Rapid NTLM lateral movement — single source, 5+ targets in 5 min	4624	T1021.002	HIGH
Rule 4	Impacket tool signatures (psexec/smbexec/wmiexec hardcoded strings)	7045, 4697, 5140	T1550.002	HIGH
Rule 5	Overpass-the-Hash — RC4 TGT request via NT hash conversion	4768	T1550.002	MEDIUM-HIGH
Rule 6	Chained TTP — LSASS access then NTLM logon from same source	Sysmon 10 + 4624	T1003.001 + T1550.002	HIGH

Prerequisites

1. Audit Policy — Enable "Audit Logon" (Success + Failure) on all domain-joined hosts
2. Audit Policy — Enable "Audit Special Logon" (Success) on all hosts
3. Audit Policy — Enable "Audit Kerberos Authentication Service" (Success + Failure) on all DCs
4. Log Forwarding — Splunk Universal Forwarder on all hosts forwarding Security logs
5. Sysmon — Deploy Sysmon with ProcessAccess (Event 10) for LSASS — required for Rule 6
6. Lookup Tables — dc_ip_list.csv (DC IPs) + legacy_ntlm_hosts.csv (legitimate NTLM consumers)

Quick Deploy

1. Deploy Rule 2 (Mimikatz LogonType 9 / seclogo) immediately — zero expected false positives
2. Deploy Rule 4 (Impacket signatures) immediately — hardcoded tool strings have near-zero FP rate
3. Deploy Rule 1 (classic PtH) after building legacy_ntlm_hosts.csv to suppress legitimate NTLM sources
4. Enable Rule 3 (rapid lateral movement) after confirming the 5-target threshold fits your environment
5. Tune Rule 5 (Overpass-the-Hash) only after enforcing AES encryption domain-wide (disabling RC4)
6. Enable Rule 6 (chained TTP) after Sysmon LSASS ProcessAccess monitoring is in place

---

Password Spraying Detection

File: splunk_rules/credential_access/password_spraying_detection.yml

Detects Password Spraying (MITRE T1110.003) and Brute Force (T1110.001) attacks through 7 complementary detection rules covering Kerberos and NTLM spray, account lockout storms, spray hit confirmation, username enumeration, and slow low-cadence APT spray patterns:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	Kerberos spray — 4771 Status=0x18, ≥10 accounts in 5 min	4771	T1110.003	HIGH
Rule 2	NTLM spray at DC — 4776 Status=0xC000006A, ≥10 accounts in 5 min	4776	T1110.003	HIGH
Rule 3	Single-account brute force — 4625, ≥20 failures, dc(account)≤2	4625	T1110.001	HIGH
Rule 4	Account lockout storm — ≥5 locked accounts in 10 min	4740	T1110.003	MEDIUM-HIGH
Rule 5	Spray hit — failures ≥10 + success from same IP within 30 min	4625 + 4624	T1110.003	HIGH
Rule 6	Kerberos username enumeration — 4768 Status=0x6, ≥10 accounts in 2 min	4768	T1087.002	HIGH
Rule 7	Slow APT spray — 24h window, ≥20 accounts, <4 attempts/account	4771, 4776	T1110.003	MEDIUM

Prerequisites

1. Audit Policy — Enable "Audit Kerberos Authentication Service" (Success + Failure) on all DCs
2. Audit Policy — Enable "Audit Credential Validation" (Success + Failure) on all DCs
3. Audit Policy — Enable "Audit Logon" (Success + Failure) on all DCs and endpoints
4. Audit Policy — Enable "Audit Account Lockout" (Success) on all DCs
5. Log Forwarding — Splunk Universal Forwarder on all DCs and endpoints forwarding Security logs

Quick Deploy

1. Deploy Rule 5 (spray hit) first — confirms successful compromise, highest priority alert
2. Deploy Rule 1 (Kerberos 4771) immediately — Kerberos spray is the most common modern technique
3. Deploy Rule 4 (lockout storm) immediately — even lagging, mass lockouts need immediate response
4. Run Rule 7 (slow spray) in report mode for 30 days before alerting to baseline your environment
5. Tune the dc(account) threshold in Rule 1 (default: 10 accounts / 5 min) using 14-day baseline data

---

Privileged Group Membership Modification Detection

File: splunk_rules/credential_access/privileged_group_membership_modification_detection.yml

Detects unauthorized modifications to privileged Active Directory groups (MITRE T1098.001) through 6 complementary detection rules covering all group types, direct LDAP writes, bulk escalation patterns, nested group abuse, and AdminSDHolder persistence:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	Member added to privileged group (all scope types)	4728, 4732, 4756	T1098.001	HIGH
Rule 2	Direct LDAP 'member' attribute write to privileged group	5136	T1098.001	HIGH
Rule 3	Bulk escalation — ≥3 privileged groups modified in 10 min	4728, 4732, 4756	T1098.001	HIGH
Rule 4	Nested group added to privileged group (inherited privilege)	4728, 4732, 4756	T1098.001	MEDIUM-HIGH
Rule 5	AdminSDHolder ACL modification — covert persistent privilege	5136	T1098.001	HIGH
Rule 6	Masquerade group creation mimicking privileged group name	4731	T1098.001	MEDIUM

Prerequisites

1. Audit Policy — Enable "Audit Security Group Management" (Success) on all DCs
2. Audit Policy — Enable "Audit Directory Service Changes" (Success) on all DCs
3. SACL — Configure auditing on CN=AdminSDHolder for Rule 5
4. Log Forwarding — Splunk Universal Forwarder on all DCs forwarding Security logs
5. Lookup Tables — privileged_group_admin_allowlist.csv for known-legitimate GPO admin accounts

Quick Deploy

1. Deploy Rule 1 immediately — direct group additions are the core detection with highest value
2. Deploy Rule 5 (AdminSDHolder) immediately — no false positives; very rare legitimate modification
3. Deploy Rule 2 (LDAP direct write) to catch BloodHound-based attacks that bypass standard events
4. Build the privileged_group_admin_allowlist.csv lookup to suppress IAM provisioning tool accounts
5. Enable Rule 3 (bulk escalation) after confirming the 3-group threshold does not fire during planned AD migrations

---

Golden Ticket Detection

File: splunk_rules/credential_access/golden_ticket_attack_detection.yml

Detects Golden Ticket Kerberos forgery attacks (MITRE T1558.001) through 6 complementary detection rules. Golden Tickets are forged TGTs signed with the KRBTGT hash — no Event 4768 is generated by the KDC, making detection rely on secondary indicators:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	RC4 TGT in AES-enforced environment	4768	T1558.001	HIGH
Rule 2	RC4 TGS request in AES-enforced environment	4769	T1558.001	MEDIUM-HIGH
Rule 3	TGS request without preceding TGT issuance (forged TGT presented)	4769 (absent 4768)	T1558.001	HIGH
Rule 4	Special privilege Kerberos logon with no TGT issuance	4672 + 4624 (absent 4768)	T1558.001	HIGH
Rule 5	Anomalous krbtgt service ticket request	4769	T1558.001	MEDIUM-HIGH
Rule 6	TGT/TGS encryption type mismatch (AES TGT + RC4 TGS)	4768 + 4769	T1558.001	MEDIUM

Prerequisites

1. Audit Policy — Enable "Audit Kerberos Authentication Service" (Success + Failure) on all DCs
2. Audit Policy — Enable "Audit Kerberos Service Ticket Operations" (Success + Failure) on all DCs
3. Audit Policy — Enable "Audit Special Logon" (Success) on all hosts
4. AES Enforcement — Domain-wide RC4 disablement via GPO required for Rule 1 and 2 to be effective
5. Log Forwarding — All DC Security logs in one Splunk index (critical for absence-of-TGT correlation)
6. Lookup Tables — rc4_tgt_allowlist.csv (legacy RC4 consumers) + privileged_accounts.csv (Rule 3 scope)

Quick Deploy

1. Deploy Rule 3 (TGS without TGT) scoped to privileged accounts only — highest-fidelity indicator
2. Deploy Rule 4 (special privilege without TGT) — combination of 4672 + 4624 + absent 4768 is definitive
3. Enable Rules 1 and 2 (RC4 anomalies) ONLY after fully enforcing AES domain-wide and building allowlists
4. Run Rules 1 and 2 in report mode for 14 days first to eliminate legacy RC4 consumers from scope
5. For environments without AES enforcement: focus on Rules 3, 4, and 6 (encryption-agnostic indicators)

---

NTDS.dit Extraction Detection

File: splunk_rules/credential_access/ntds_dit_extraction_detection.yml

Detects NTDS.dit Active Directory database extraction (MITRE T1003.003) through 8 complementary detection rules covering all major extraction techniques — ntdsutil IFM, VSS-based copies, LOLBin abuse, PowerShell WMI, and file-level SACL auditing:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	ntdsutil IFM execution on DC	4688, Sysmon 1	T1003.003	HIGH
Rule 2	vssadmin shadow copy creation on DC	4688, Sysmon 1	T1003.003	HIGH
Rule 3	diskshadow /s script mode on DC	4688, Sysmon 1	T1003.003	HIGH
Rule 4	esentutl /y /vss copy of NTDS.dit	4688, Sysmon 1	T1003.003	HIGH
Rule 5	PowerShell Win32_ShadowCopy + NTDS file copy	4104	T1003.003	HIGH
Rule 6	ntds.dit file created outside NTDS directory	Sysmon 11	T1003.003	HIGH
Rule 7	NTDS.dit direct file access via SACL audit	4663	T1003.003	MEDIUM-HIGH
Rule 8	Multi-stage correlation — VSS creation + ntds.dit copy	Sysmon 1 + 11	T1003.003	HIGH

Prerequisites

1. Process Creation Logging — Enable "Audit Process Creation" (Success) with command-line on all DCs
2. PowerShell Logging — Enable Script Block Logging via GPO on all DCs
3. Sysmon Deployment — Deploy Sysmon on DCs with ProcessCreate (Event 1), FileCreate (Event 11)
4. SACL on NTDS.dit — Configure Everyone: Read Data auditing on %SystemRoot%\NTDS\ntds.dit for Rule 7
5. Log Forwarding — Splunk Universal Forwarder on all DCs forwarding Security + Sysmon + PowerShell logs
6. DC Hostname Lookup — dc_hostnames.csv to restrict vssadmin/diskshadow alerts to DCs only

Quick Deploy

1. Deploy Rule 1 (ntdsutil IFM) immediately — highest fidelity, almost no legitimate use outside DCPromo
2. Deploy Rule 6 (ntds.dit outside NTDS path via Sysmon 11) — tool-agnostic, catches any extraction method
3. Deploy Rule 8 (kill chain correlation) for the highest-confidence, lowest-FP combined indicator
4. Deploy Rules 2–5 after populating dc_hostnames.csv to avoid false positives on non-DC servers
5. Configure SACL on NTDS.dit on all DCs to enable Rule 7 (file-level access audit)

---

GPO Modification Detection

File: splunk_rules/credential_access/gpo_modification_detection.yml

Detects malicious Group Policy Object modification (MITRE T1484.001) through 7 complementary detection rules covering AD-layer GPO changes, SYSVOL payload injection, built-in policy tampering, security control disabling, and kill-chain correlation:

Rule	Detection Method	Event IDs	Technique	Confidence
Rule 1	Unauthorized GPO attribute modification in AD	5136	T1484.001	HIGH
Rule 2	New GPO created and linked to domain root or DC OU	5137 + 5136	T1484.001	HIGH
Rule 3	Malicious script/task file written to SYSVOL GPO directory	Sysmon 11	T1484.001	HIGH
Rule 4	SharpGPOAbuse / StandIn / PowerGPOAbuse tool detection	4688, Sysmon 1, 4104	T1484.001	HIGH
Rule 5	Default Domain Policy or Default DC Policy modified	5136	T1484.001	HIGH
Rule 6	GPO used to disable Windows security controls (Defender, Firewall, WDigest)	5136, Sysmon 11	T1484.001, T1562.001	HIGH
Rule 7	Multi-stage kill chain — AD GPO change + SYSVOL write correlated	5136 + Sysmon 11	T1484.001	HIGH

Prerequisites

1. Audit Policy — Enable "Audit Directory Service Changes" (Success) on all DCs
2. Audit Policy — Enable "Audit Directory Service Object Created" (Success) for Event 5137
3. Sysmon Deployment — Deploy Sysmon on DCs with FileCreate (Event 11) targeting SYSVOL paths
4. Process Creation Logging — Enable "Audit Process Creation" with command-line on all DCs/endpoints
5. PowerShell Logging — Enable Script Block Logging via GPO for PowerShell-based GPO abuse detection
6. Lookup Tables — gpo_admin_allowlist.csv with authorised GPO administrator accounts

Quick Deploy

1. Deploy Rule 5 (Default Domain/DC Policy) immediately — any change here has domain-wide impact
2. Deploy Rule 3 (SYSVOL payload write via Sysmon 11) — tool-agnostic, catches the payload regardless of attack method
3. Deploy Rule 4 (tool signatures) immediately — SharpGPOAbuse/StandIn strings have zero FP rate
4. Deploy Rule 6 (security control disabling) — disable-Defender patterns require no baseline period
5. Build gpo_admin_allowlist.csv before enabling Rule 1 to suppress legitimate GPO administrators
6. Enable Rule 7 (kill chain) after Rules 1 and 3 are confirmed operational

---

RHEL Linux Detection Rules

Detection rules for Red Hat Enterprise Linux attack techniques across 8 MITRE ATT&CK tactics. Covers the full attack lifecycle from initial discovery through privilege escalation, persistence, credential access, defense evasion, execution, lateral movement, and exfiltration. 63 detection rules + 40 investigation queries + 8 incident response playbooks.

Rule Summary

Rule File	Attack Technique	MITRE ID	Severity	Detection Vectors
rhel_privilege_escalation_detection.yml	Sudo Abuse, SUID/SGID, Kernel Exploits, Container Escape	T1548.003, T1548.001, T1068, T1611	HIGH–CRITICAL	8 rules + 5 investigation queries
rhel_persistence_detection.yml	Cron, Systemd, SSH Keys, PAM, LD_PRELOAD, Shell Profiles	T1053.003, T1543.002, T1098.004, T1556.003, T1574.006, T1546.004	HIGH–CRITICAL	9 rules + 5 investigation queries
rhel_credential_access_detection.yml	Shadow File, SSH Key Theft, Brute Force, Ptrace, Keylogger	T1003.008, T1552.004, T1110.001, T1003, T1056.001	HIGH–CRITICAL	8 rules + 5 investigation queries
rhel_defense_evasion_detection.yml	Auditd Tampering, Log Deletion, SELinux, Rootkits, Timestomping	T1562.001, T1070.002, T1070.006, T1014, T1036.004	HIGH–CRITICAL	9 rules + 5 investigation queries
rhel_execution_detection.yml	Reverse Shells, Webshells, Fileless, Log4Shell, Ptrace Injection	T1059.004, T1059.006, T1620, T1505.003, T1055.008, T1203	HIGH–CRITICAL	8 rules + 5 investigation queries
rhel_lateral_movement_detection.yml	SSH Tunneling, Agent Forwarding, SCP/Rsync, Network Scanning	T1021.004, T1572, T1563.001, T1072, T1046, T1210	MEDIUM–CRITICAL	7 rules + 5 investigation queries
rhel_discovery_enumeration_detection.yml	LinPEAS/LinEnum, System Recon, User Enum, Container Discovery	T1059.004, T1082, T1087.001, T1016, T1518.001, T1613	MEDIUM–HIGH	7 rules + 5 investigation queries
rhel_exfiltration_detection.yml	DNS Tunneling, HTTP Upload, Archive Staging, Encoded Data	T1560.001, T1048.003, T1048.002, T1132.001, T1119	HIGH–CRITICAL	7 rules + 5 investigation queries

---

RHEL Privilege Escalation Detection

File: splunk_rules/rhel_linux/rhel_privilege_escalation_detection.yml

Detects Linux privilege escalation techniques (MITRE T1548, T1068, T1611) through 8 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	Sudo abuse — unauthorized sudo, sudo to root shell	auditd EXECVE	T1548.003	HIGH
Rule 2	Sudoers file modification — visudo bypass, echo injection	auditd SYSCALL/PATH	T1548.003	HIGH
Rule 3	SUID/SGID binary exploitation — find/vim/nmap/python	auditd EXECVE	T1548.001	HIGH
Rule 4	Kernel exploit indicators — dirty pipe/cow, exploit compilation	auditd EXECVE, syslog	T1068	CRITICAL
Rule 5	Linux capabilities abuse — cap_setuid, cap_dac_override	auditd EXECVE	T1548	HIGH
Rule 6	PwnKit / Polkit exploitation (CVE-2021-4034)	auditd EXECVE, syslog	T1068	CRITICAL
Rule 7	Container escape to host — nsenter, mount /proc, chroot	auditd EXECVE	T1611	CRITICAL
Rule 8	Cgroup escape — notify_on_release abuse	auditd EXECVE/SYSCALL	T1611	CRITICAL

---

RHEL Persistence Detection

File: splunk_rules/rhel_linux/rhel_persistence_detection.yml

Detects Linux persistence mechanisms (MITRE T1053, T1543, T1098, T1556, T1574, T1546, T1037, T1547) through 9 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	Malicious cron job — reverse shells, download-and-execute	auditd SYSCALL/PATH	T1053.003	HIGH
Rule 2	Rogue systemd service — ExecStart pointing to /tmp, /dev/shm	auditd SYSCALL, syslog	T1543.002	HIGH
Rule 3	SSH authorized_keys injection — unauthorized key addition	auditd SYSCALL/PATH	T1098.004	HIGH
Rule 4	PAM backdoor module — pam_exec, custom .so in /lib/security	auditd SYSCALL	T1556.003	CRITICAL
Rule 5	LD_PRELOAD hijacking — /etc/ld.so.preload, LD_PRELOAD env	auditd EXECVE, SYSCALL	T1574.006	CRITICAL
Rule 6	Shell profile backdoor — .bashrc, .bash_profile, /etc/profile.d	auditd SYSCALL/PATH	T1546.004	HIGH
Rule 7	Malicious at job scheduling	auditd EXECVE	T1053.002	HIGH
Rule 8	Init script / rc.local persistence	auditd SYSCALL	T1037.004	HIGH
Rule 9	Kernel module persistence — insmod, modprobe from non-standard path	auditd SYSCALL	T1547.006	CRITICAL

---

RHEL Credential Access Detection

File: splunk_rules/rhel_linux/rhel_credential_access_detection.yml

Detects Linux credential theft techniques (MITRE T1003, T1552, T1110, T1056, T1558) through 8 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	/etc/shadow access — unshadow, cat/cp shadow, john/hashcat	auditd SYSCALL/EXECVE	T1003.008	CRITICAL
Rule 2	SSH private key theft — copying id_rsa, .pem from .ssh dirs	auditd SYSCALL/EXECVE	T1552.004	HIGH
Rule 3	SSH brute force — ≥10 failed auth in 5 min from single source	linux_secure	T1110.001	HIGH
Rule 4	Ptrace-based credential dumping — gdb attach, strace on sshd	auditd SYSCALL	T1003	HIGH
Rule 5	Keylogger installation — xinput, logkeys, pam_tty_audit	auditd EXECVE	T1056.001	HIGH
Rule 6	Credential files in non-standard locations — .netrc, .pgpass, .my.cnf	auditd EXECVE	T1552.001	MEDIUM-HIGH
Rule 7	Kerberos keytab theft — ktutil, klist, keytab file copy	auditd EXECVE/SYSCALL	T1558.004	HIGH
Rule 8	LDAP credential harvesting — ldapsearch with password attributes	auditd EXECVE	T1003	HIGH

---

RHEL Defense Evasion Detection

File: splunk_rules/rhel_linux/rhel_defense_evasion_detection.yml

Detects Linux defense evasion techniques (MITRE T1562, T1070, T1014, T1036) through 9 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	Auditd tampering — service stop, auditctl -e 0, config modification	auditd SYSCALL/EXECVE	T1562.001	CRITICAL
Rule 2	Log deletion — rm/shred/truncate on /var/log files	auditd EXECVE	T1070.002	CRITICAL
Rule 3	Timestomping — touch -t, touch -r to alter file timestamps	auditd EXECVE	T1070.006	HIGH
Rule 4	SELinux disabling — setenforce 0, SELINUX=disabled	auditd EXECVE, syslog	T1562.001	CRITICAL
Rule 5	Firewall tampering — iptables -F, firewalld stop, ufw disable	auditd EXECVE	T1562.004	HIGH
Rule 6	Rootkit indicators — hidden kernel modules, /dev/shm binaries, LD_PRELOAD	auditd EXECVE, syslog	T1014	CRITICAL
Rule 7	Process masquerading — renamed binaries mimicking system processes	sysmon_linux Event 1	T1036.004	HIGH
Rule 8	History tampering — HISTFILE=/dev/null, unset HISTFILE, history -c	auditd EXECVE	T1070.003	HIGH
Rule 9	Binary replacement — overwriting system binaries (ps, ls, netstat)	auditd SYSCALL/PATH	T1036.005	CRITICAL

---

RHEL Execution Detection

File: splunk_rules/rhel_linux/rhel_execution_detection.yml

Detects Linux malicious execution techniques (MITRE T1059, T1620, T1505, T1105, T1055, T1203) through 8 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	Reverse shell execution — bash -i, nc -e, python pty.spawn	auditd EXECVE	T1059.004	CRITICAL
Rule 2	Suspicious script interpreters — python/perl/ruby one-liners from /tmp	auditd EXECVE	T1059.006	HIGH
Rule 3	Fileless execution — memfd_create, /proc/self/fd, shm_open	auditd SYSCALL/EXECVE	T1620	CRITICAL
Rule 4	Webshell execution — www-data/apache spawning shell commands	auditd EXECVE	T1505.003	CRITICAL
Rule 5	Download-and-execute — curl/wget piped to bash/sh	auditd EXECVE	T1105	HIGH
Rule 6	Cron-based suspicious execution — cron spawning network tools	auditd EXECVE, syslog	T1053.003	HIGH
Rule 7	Ptrace code injection — PTRACE_POKETEXT into running processes	auditd SYSCALL	T1055.008	CRITICAL
Rule 8	Application exploitation — Log4Shell, Struts, Spring indicators	syslog, auditd	T1203	CRITICAL

---

RHEL Lateral Movement Detection

File: splunk_rules/rhel_linux/rhel_lateral_movement_detection.yml

Detects Linux lateral movement techniques (MITRE T1021, T1572, T1563, T1072, T1105, T1046, T1210) through 7 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	Unusual outbound SSH — connections to non-standard ports or IPs	auditd EXECVE, sysmon_linux Event 3	T1021.004	MEDIUM-HIGH
Rule 2	SSH tunneling — dynamic (-D) and local (-L) port forwarding	auditd EXECVE	T1572	HIGH
Rule 3	SSH agent forwarding abuse — ForwardAgent, SSH_AUTH_SOCK hijack	auditd EXECVE	T1563.001	HIGH
Rule 4	Config management abuse — Ansible/Puppet/Salt ad-hoc commands	auditd EXECVE	T1072	MEDIUM-HIGH
Rule 5	Suspicious SCP/rsync — bulk file transfer to external hosts	auditd EXECVE, sysmon_linux	T1105	HIGH
Rule 6	Internal network scanning — nmap, masscan, zmap from non-scanner hosts	auditd EXECVE	T1046	HIGH
Rule 7	Internal service exploitation — exploit frameworks targeting internal IPs	auditd EXECVE, sysmon_linux	T1210	CRITICAL

---

RHEL Discovery & Enumeration Detection

File: splunk_rules/rhel_linux/rhel_discovery_enumeration_detection.yml

Detects Linux reconnaissance and discovery techniques (MITRE T1059, T1082, T1087, T1016, T1518, T1083, T1613) through 7 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	LinPEAS / LinEnum execution — known enumeration script names and hashes	auditd EXECVE	T1059.004	HIGH
Rule 2	System information discovery burst — ≥5 recon commands in 2 min	auditd EXECVE	T1082	HIGH
Rule 3	User and group enumeration — /etc/passwd read, getent, id commands	auditd EXECVE	T1087.001	MEDIUM
Rule 4	Network configuration discovery — ip route, ss, netstat, arp -a	auditd EXECVE	T1016	MEDIUM
Rule 5	Security software discovery — querying AV, EDR, audit daemon status	auditd EXECVE	T1518.001	HIGH
Rule 6	Sensitive file discovery — find / -name *.pem, locate shadow	auditd EXECVE	T1083	HIGH
Rule 7	Container and cloud metadata discovery — docker inspect, curl 169.254	auditd EXECVE	T1613	HIGH

---

RHEL Exfiltration Detection

File: splunk_rules/rhel_linux/rhel_exfiltration_detection.yml

Detects Linux data exfiltration techniques (MITRE T1560, T1048, T1132, T1119) through 7 complementary detection rules:

Rule	Detection Method	Data Source	Technique	Confidence
Rule 1	Archive staging — tar/zip of sensitive directories (/etc, /home, DB dumps)	auditd EXECVE	T1560.001	HIGH
Rule 2	DNS tunneling exfiltration — iodine, dnscat2, dns2tcp, high TXT query volume	auditd EXECVE, sysmon_linux	T1048.003	CRITICAL
Rule 3	HTTP exfiltration — curl/wget POST with file upload to external hosts	auditd EXECVE	T1048.002	HIGH
Rule 4	SSH/SCP exfiltration — bulk SCP/sftp to external IPs	auditd EXECVE	T1048	HIGH
Rule 5	Encoded data staging — base64/xxd/openssl encoding of sensitive files	auditd EXECVE	T1132.001	HIGH
Rule 6	Automated collection — scripted find/grep harvesting credentials and configs	auditd EXECVE	T1119	HIGH
Rule 7	Alternative protocol exfiltration — netcat, socat, /dev/tcp to external IPs	auditd EXECVE	T1048	CRITICAL

---

RHEL Data Sources

All RHEL rules rely on the following Splunk data sources:

Sourcetype	Description	Index
linux:audit	auditd EXECVE, SYSCALL, PATH events (primary source)	linux
syslog	/var/log/messages, syslog daemon output	linux
linux_secure	/var/log/secure — SSH auth, sudo, PAM events	linux
sysmon_linux	Sysmon for Linux — Events 1 (ProcessCreate), 3 (NetworkConnect), 11 (FileCreate)	linux

RHEL Prerequisites

1. auditd Configuration — Deploy comprehensive audit rules covering EXECVE, SYSCALL, PATH, and key file watches (-w /etc/shadow -p rwa, -w /etc/sudoers -p wa, etc.)
2. Sysmon for Linux — Deploy Sysmon for Linux on all RHEL hosts for process, network, and file creation telemetry
3. Log Forwarding — Splunk Universal Forwarder on all RHEL hosts forwarding /var/log/audit/audit.log, /var/log/secure, /var/log/messages
4. Lookup Tables:
   • linux_bastion_hosts.csv — bastion/jump hosts and configuration management servers
   • linux_admin_accounts.csv — authorized admin and sudo accounts
   • linux_server_inventory.csv — host roles, environments, and expected services

RHEL Quick Deploy

1. Deploy Defense Evasion rules first — if an attacker disables auditd or deletes logs, all other detections fail
2. Deploy Privilege Escalation rules next — sudo abuse and kernel exploits are the most common RHEL attack patterns
3. Deploy Execution rules (reverse shells, webshells) for immediate high-fidelity alerting
4. Deploy Persistence rules to catch implant installation (cron, systemd, SSH keys)
5. Deploy Credential Access rules — shadow file access and SSH key theft are critical indicators
6. Deploy Lateral Movement and Exfiltration rules last — these benefit from the bastion host lookup table being fully populated
7. Run Discovery/Enumeration rules in report mode for 14 days before alerting to establish a baseline of normal admin activity

---

Detection Rules -- Apache Web Server

Detection rules for attacks targeting Apache HTTP Server across 6 attack categories. Covers the full web attack lifecycle from reconnaissance through exploitation, persistence, and denial of service. 37 detection rules + 24 investigation queries + 6 incident response playbooks.

Rule Summary

Rule File	Attack Category	MITRE Techniques	Severity	Detection Vectors
apache_path_traversal_detection.yml	Path Traversal, LFI, CVE-2021-41773/42013	T1190, T1083, T1005	HIGH--CRITICAL	5 rules + 5 investigation queries
apache_web_shell_detection.yml	Web Shell Upload, Execution, Beaconing	T1505.003, T1059.004, T1071.001	HIGH--CRITICAL	7 rules + 5 investigation queries
apache_sqli_xss_detection.yml	SQL Injection, XSS, Scanner Detection	T1190, T1059.007	HIGH--CRITICAL	6 rules + 4 investigation queries
apache_brute_force_dos_detection.yml	HTTP Brute Force, Credential Stuffing, DDoS	T1110, T1498, T1499	MEDIUM--CRITICAL	6 rules + 5 investigation queries
apache_reconnaissance_detection.yml	Scanner Fingerprinting, Directory Enum, Probing	T1595.002, T1083, T1046	MEDIUM--HIGH	6 rules + 4 investigation queries
apache_exploitation_detection.yml	Shellshock, Log4Shell, Struts, SSRF, SSTI	T1190, T1059.004, T1210	HIGH--CRITICAL	7 rules + 5 investigation queries

---

Apache Path Traversal Detection

File: splunk_rules/apache_webserver/apache_path_traversal_detection.yml

Rule	Detection Method	CVE	Confidence
Rule 1	CVE-2021-41773 Apache 2.4.49 .%2e normalization bypass	CVE-2021-41773	VERY HIGH
Rule 2	CVE-2021-42013 Apache 2.4.50 double-encoding bypass (%%32%65)	CVE-2021-42013	VERY HIGH
Rule 3	Generic directory traversal (../, %2e%2e, overlong UTF-8, %c0%ae)	--	HIGH
Rule 4	Null byte injection (%00) for extension bypass	--	HIGH
Rule 5	Local File Inclusion via /proc/self/environ	--	HIGH

---

Apache Web Shell Detection

File: splunk_rules/apache_webserver/apache_web_shell_detection.yml

Rule	Detection Method	Shell Coverage	Confidence
Rule 1	File upload via HTTP POST to writable web directory	All	HIGH
Rule 2	Script file created in web root by Apache process (Sysmon/auditd)	All	VERY HIGH
Rule 3	Suspicious URI parameters (cmd=, exec=, base64 payloads)	China Chopper, Godzilla, Behinder	HIGH
Rule 4	Apache process spawning OS commands (server-side)	All	VERY HIGH
Rule 5	Known web shell file hash matching (SHA256 lookup)	All	VERY HIGH
Rule 6	Periodic POST beaconing to single script file (C2 pattern)	Godzilla, Behinder, Weevely	MEDIUM-HIGH
Rule 7	Script access from unusual geographic source	All	MEDIUM

---

Apache SQL Injection & XSS Detection

File: splunk_rules/apache_webserver/apache_sqli_xss_detection.yml

Rule	Detection Method	Attack Type	Confidence
Rule 1	UNION SELECT, INTO OUTFILE, INFORMATION_SCHEMA	UNION-based SQLi	HIGH
Rule 2	SLEEP(), BENCHMARK(), WAITFOR, pg_sleep(), boolean-based	Blind/Time-based SQLi	HIGH
Rule 3	' OR 1=1--, admin'--, tautology bypasses	Auth Bypass SQLi	HIGH
Rule 4	<script>, javascript:, onerror=, event handlers	Reflected XSS	HIGH
Rule 5	High-volume diverse payloads from single IP (sqlmap, XSSer)	Automated Scanner	HIGH
Rule 6	MySQL/PostgreSQL/Oracle/MSSQL error messages in error log	Error-based SQLi	VERY HIGH

---

Apache Brute Force & DoS Detection

File: splunk_rules/apache_webserver/apache_brute_force_dos_detection.yml

Rule	Detection Method	Attack Type	Confidence
Rule 1	HTTP 401 storm from single IP (20+ in 5 min)	Basic/Digest Auth Brute Force	HIGH
Rule 2	Rapid POST to login endpoints (15+ in 5 min)	Web Login Brute Force	HIGH
Rule 3	Many unique IPs, 1-3 attempts each (distributed)	Credential Stuffing	MEDIUM-HIGH
Rule 4	MaxRequestWorkers exhaustion, scoreboard full	Slowloris / Slow HTTP DoS	HIGH
Rule 5	500+ requests/min from single IP	HTTP Flood DDoS	HIGH
Rule 6	20+ unique 403 paths from single IP	Access Control Probing	MEDIUM-HIGH

---

Apache Reconnaissance Detection

File: splunk_rules/apache_webserver/apache_reconnaissance_detection.yml

Rule	Detection Method	Tool Coverage	Confidence
Rule 1	Known scanner User-Agent matching	Nikto, Nmap, Nuclei, WPScan, SQLMap, Burp, ZAP, Acunetix	HIGH
Rule 2	50+ unique 404 paths in 5 min (forced browsing)	DirBuster, Gobuster, ffuf, feroxbuster	HIGH
Rule 3	Probing .git, .env, .htpasswd, phpinfo, backups, server-status	All	HIGH
Rule 4	OPTIONS, TRACE, DEBUG, PUT, DELETE method probing	All	MEDIUM-HIGH
Rule 5	Admin panel discovery (/admin, /phpmyadmin, /jenkins, /grafana)	All	HIGH
Rule 6	WordPress user, plugin, and REST API enumeration	WPScan, custom	HIGH

---

Apache Exploitation Detection

File: splunk_rules/apache_webserver/apache_exploitation_detection.yml

Rule	Detection Method	CVE / Attack	Confidence
Rule 1	Shellshock () { :; }; in HTTP headers targeting CGI	CVE-2014-6271	VERY HIGH
Rule 2	Log4Shell ${jndi:ldap://} and obfuscated variants	CVE-2021-44228	VERY HIGH
Rule 3	Apache Struts OGNL injection in Content-Type	CVE-2017-5638	VERY HIGH
Rule 4	SSRF targeting cloud metadata, internal IPs, file://	CVE-2021-40438, generic	HIGH
Rule 5	HTTP request smuggling (CL.TE / TE.CL desync)	Generic	HIGH
Rule 6	Server-Side Template Injection (Jinja2, Twig, Freemarker)	Generic SSTI	HIGH
Rule 7	OS command injection via pipe, semicolon, backtick	Generic	HIGH

---

Apache Data Sources

All Apache detection rules rely on the following Splunk data sources:

Sourcetype	Description	Index
access_combined	Apache Combined Log Format access logs (primary)	web
access_common	Apache Common Log Format access logs	web
apache:error	Apache error log (mod_security, SQL errors, connection exhaustion)	web
sysmon_linux	Sysmon for Linux — process creation, file creation, network connections	linux
linux:audit	auditd EXECVE, SYSCALL, file watch events	linux

Apache Prerequisites

1. Apache Access Logs -- Forward access logs in Combined Log Format to Splunk (index=web, sourcetype=access_combined)
2. Apache Error Logs -- Forward error logs to Splunk (index=web, sourcetype=apache:error)
3. Sysmon for Linux -- Deploy on web servers for process creation (Event 1), file creation (Event 11), and image load (Event 7) telemetry
4. auditd -- Configure file watches on web root directories: -w /var/www -p wa -k web_write
5. Lookup Tables:
   • webshell_hashes.csv -- known web shell SHA256 hashes from threat intel feeds
   • Scanner/pentest IP allowlists for false positive suppression

Apache Quick Deploy

1. Deploy Exploitation rules first (Shellshock, Log4Shell, Struts) -- zero false positives, immediate critical alerting
2. Deploy Path Traversal rules (CVE-2021-41773/42013) -- near-zero FP, catches active exploitation
3. Deploy Web Shell Rule 4 (Apache spawning OS commands) -- highest-confidence server-side indicator
4. Deploy SQLi/XSS rules -- tune UNION/blind SQLi thresholds during a 7-day baseline
5. Deploy Brute Force rules after baselining normal login failure rates
6. Deploy Reconnaissance rules last -- informational, useful for threat profiling

---

Recent Attack Campaign Detection

Detection rules for active threat campaigns and recently disclosed CVEs.

Rule File	Threat Actor / CVE	MITRE ID	Severity	Detection Vectors
cve_2026_21509_apt28_operation_neusploit_detection.yml	UAC-0001 (APT28) / CVE-2026-21509	T1203, T1559.001, T1547.012, T1071.001	CRITICAL	12 rules + 7 investigation queries + IR playbook

CVE-2026-21509 -- APT28 Operation Neusploit

File: splunk_rules/recent_attacks/cve_2026_21509_apt28_operation_neusploit_detection.yml

Detects APT28 (UAC-0001) exploitation of CVE-2026-21509 (Microsoft Office OLE Security Feature Bypass via Shell.Explorer.1 COM object) through 12 detection rules covering two attack variants -- MiniDoor (Outlook email stealer) and PixyNetLoader (COM-hijacking loader with steganographic shellcode):

Rule	Detection Method	Data Source	Confidence
Rule 1	Office child process spawning cmd/powershell/mshta	Sysmon 1, 4688	HIGH
Rule 2	Office outbound connections to non-standard ports	Sysmon 3	HIGH
Rule 3	Known C2 domains (freefoodaid.com, wellnesscaremed.com)	DNS, Proxy	CRITICAL
Rule 4	File hash IOC matching (12 SHA256 + 6 MD5)	Sysmon 1/7/11	CRITICAL
Rule 5	PixyNetLoader COM hijacking (CLSID D9144DCD)	Sysmon 13	CRITICAL
Rule 6	MiniDoor Outlook macro security downgrade	Sysmon 13	HIGH
Rule 7	File staging in suspicious paths (AppData, Temp)	Sysmon 11	HIGH
Rule 8	OneDriveHealth scheduled task persistence	Sysmon 1, 4698	HIGH
Rule 9	Outlook VBA email theft indicators	Sysmon 1, 4104	HIGH
Rule 10	Explorer.exe suspicious DLL side-load	Sysmon 7	HIGH
Rule 11	Shell.Explorer.1 COM instantiation from Office	Sysmon 1, 4104	HIGH
Rule 12	Full kill chain correlation (multi-stage)	Combined	CRITICAL

---

Requirements

• Splunk Enterprise 8.x+ or Splunk Cloud
• Splunk Enterprise Security (ES) recommended for notable events and risk framework

Windows AD Detection Rules

• Windows Security Event Logs from all endpoints (sourcetype: XmlWinEventLog:Security)
• Sysmon deployed on all endpoints (sourcetype: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational)
• PowerShell logs from all endpoints (sourcetype: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational)
• PowerShell 5.1+ on endpoints for audit policy configuration

RHEL Linux Detection Rules

• auditd deployed and configured on all RHEL hosts (sourcetype: linux:audit)
• Sysmon for Linux deployed on all RHEL hosts (sourcetype: sysmon_linux)
• SSH/PAM logs forwarded from all RHEL hosts (sourcetype: linux_secure)
• Syslog forwarded from all RHEL hosts (sourcetype: syslog)
• Splunk Universal Forwarder on all RHEL hosts

Apache Web Server Detection Rules

• Apache access logs in Combined Log Format (sourcetype: access_combined)
• Apache error logs (sourcetype: apache:error)
• Sysmon for Linux on web servers for process and file creation telemetry (sourcetype: sysmon_linux)
• auditd with file watches on web root directories (sourcetype: linux:audit)
• Splunk Universal Forwarder on all Apache web servers