A common misconception is that if a piece of code, such as an application, has been signed, it’s clean and safe to install. Wrong!
According to Jarno Niemelä of F-Secure, there are literally tens of thousands of instances of malware in the wild that are signed.
How does this happen? There are plenty of ways to get a certificate into malware:
- Copying Certificate information from clean files
- Selfsigned certs with fake name
- MD5 forgery
- Get certified and be evil
- Get certificate with misleading name
- Get certificate with misleading name
- Find someone to sign your stuff for you
- Steal a certificate
- Infect developers system and get signed with software release
Bottom line, the certificate is worth the paper it’s printed on, so be careful what you go and install! It’s a jungle out there!
PDF of the report can be found here.






