Code signing
Code signing attaches a digital signature to software so a verifier can check its signing identity and whether the signed content has changed.
What a valid signature tells you
With Microsoft’s Authenticode, a verifier checks the publisher’s signing identity, the signature, and the relevant certificate trust requirements. It can detect changes to the signed content after signing. A familiar filename or icon provides neither check.
The signature does not tell you whether the program’s behavior is acceptable. A publisher can sign unwanted code, and software approved for one job may be inappropriate for another. On macOS, Apple describes signature and notarization checks as separate parts of Gatekeeper’s assessment.
Use the result in an installation decision
Check that the signing identity belongs to the software you intended to obtain, and keep its version and distribution source with the review. Then consider the access it requests. A valid signature does not answer why an app needs Full Disk Access, for example; the request guide covers that decision.
Later releases deserve attention too. The browser-extension article shows how a change in publishing authority can affect existing users, though browser extensions and desktop executables do not all use the same signing model.
Search ads to execution follows an installation through to endpoint activity. Signing checks help establish what was supplied; investigation establishes what it did.