Spoofed Extensions

• Description: This common and relatively simple technique involves disguising an executable file (typically .exe, but could also apply to scripts like .bat or .ps1) by changing its file extension to something seemingly innocuous or unrelated. For example, SuperClicker.exe might be renamed to important_notes.txt, config.dll, logo.png, tempdata.tmp, or even just mydata (no extension).

• Mechanism: The bypass relies on the fact that while double-clicking a file typically relies on its extension for execution, Windows offers alternative methods to launch processes that do not solely depend on the .exe extension. Common methods include:

  • Using PowerShell commands like Start-Process C:\path\to\renamed_file.tmp.

  • Using specific Windows Management Instrumentation (WMI) commands, particularly wmic process call create "C:\path\to\renamed_file.dat".

  • Utilizing scheduled tasks or other scripting methods that specify the exact file to run, regardless of extension.

• Why Cheaters Use It: The goal is to evade simple visual scans and automated tools that might primarily flag or search for standard executable extensions like .exe. A file named graphics.dll or image.png is less likely to draw immediate suspicion than MegaAimAssist.exe.

• Detection:

  • Prefetch Analysis: As mentioned previously, Prefetch often still logs the execution but under the spoofed name (e.g., LOGO.PNG-HASH.pf). Finding non-.exe files in Prefetch is a major red flag.

  • Process Memory Analysis: Tools like System Informer, when used to search service memory (especially csrss.exe, dps), can reveal the full paths of executed files, including those with spoofed extensions, using appropriate regex patterns (e.g., ^!![A-Z]((?!Exe).)*$ in DPS, or broad path searches in csrss).

  • Signature/Content Analysis: Running signature checks (like BACA's Signature Checker script) on all suspicious files found (regardless of extension) can identify executables masquerading as other file types (they'll show as "NotSigned" or "HashMismatch" if a fake signature was attempted). Tools like Detect It Easy or searching file content for PE headers (content:"This program cannot be run in DOS mode.") in Search Everything can also expose disguised executables.

  • Execution Logs: BAM, Activities Cache, and sometimes Event Logs might record the execution under the spoofed name.