Regsvr32/Rundll32 LOLBin Proxy Execution (Squiblydoo, MiniDump, JS)
Detects the abuse of signed Windows system binaries regsvr32.exe and rundll32.exe for proxy execution, defense evasion, and credential access. The rule identifies suspicious command-line patterns including Squiblydoo (regsvr32 with remote scriptlets), rundll32 executing JavaScript via mshtml.dll, rundll32 performing LSASS credential dumping via comsvcs.dll, and the loading of DLLs from untrusted user-writable locations like Temp or Downloads folders.
Sigma
