The problem is described in the article AutoIt and Malware.
Use the AutoIt3-Script-Starter to avoid false virus positives.
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AutoIt and script files should be located in a folder named AutoIt.
The Starter-file and the Script-file must have the same name (any name).
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Starter.ini
The Starter-file and the INI-file must have the same name (any name).
If the folder path is specified, a trailing backslash is required.
64-bit-Starter will prefer AutoIt3_x64.exe, unless otherwise specified in the INI file.
Starter will prefer compiled .a3x, unless otherwise specified in the INI file.