The windows XP sigverif tool is useful for identifying non-signed executables, but does not seem to be amenable to scripting -- is there a command line equivalent?
I don't think there is a direct command line equivalent, but there are a couple of things that could get you close.
Second, if you want to go down the PowerShell path, you could use the
I've used sysinternals sigcheck.exe:
Sigcheck v1.66 - File version and signature viewer Copyright (C) 2004-2010 Mark Russinovich Sysinternals - www.sysinternals.com
usage: sigcheck [-a][-h][-i][-e][-n][[-s]|[-v]|[-m]][-q][-r][-u][-c catalog file]
-a Show extended version information
-c Look for signature in the specified catalog file
-e Scan executable images only (regardless of their extension)
-h Show file hashes
-i Show catalog name and image signers
-m Dump manifest
-n Only show file version number
-q Quiet (no banner)
-r Check for certificate revocation
-s Recurse subdirectories
-u Show unsigned files only
-v Csv output
I have not tried this myself, but I believe signtool has a command line option to verify signatures.