Your PC is misbehaving. Is it malware? Faulty software, maybe? Scanning for PC for digitally signed files can help to pick out trustworthy executables, and highlight unsigned files for more investigation.

Sysinternals’ Sigcheck provides a vast amount of information and options, but it’s also a console tool, maybe inconvenient if you don’t use it enough to learn the various switches.

SigcheckGUI is a portable free alternative, a front-end for Sigcheck which allows you to set it up in a few clicks, and adds a few bonus features as well.

You’ll probably start by choosing your scan targets. These can be specific files, the contents of a folder tree, or all running processes.

(Scanning can take a very long time – tens of minutes – so we’d recommend starting with a test folder to assess the speed, before pointing the program at \Windows.)

Unsigned executables are highlighted in red (including SigcheckGUI, unfortunately)

SigcheckGUI doesn’t check VirusTotal by default, for performance reasons. If that’s a problem, click the Options tab and check “Query VirusTotal” to turn the feature on.

Whatever you choose is scanned, and details are displayed about each file: whether it’s signed or unsigned, the signing date, publisher, description, product name, product/ file/ binary version, whether it’s 32 or 64-bit, its original name, internal name, copyright, comments, hashes, path, and – optionally – VirusTotal score.

Unsigned files are highlighted in red, making them easy to spot. This doesn’t mean they’re dangerous – even SigcheckGUI.exe is unsigned, ironically – but you’ll at least get some ideas about what to check next.

Right-clicking any file displays options to help you investigate further. You’re able to open the file location, run web searches, open a VirusTotal URL for the file, and more.

SigcheckGUI’s interface isn’t great, and we noticed one or two minor bugs in our tests (right-clicking a file and selecting Open File Location didn’t always work).

The program carries out its main tasks without difficulty, though, and overall it can be a useful way to find malicious or unwanted software.

SigcheckGUI is a free application for Windows XP and later.