Signatures are regularly updated Comodo Signature Database the criticisms that have been prevalent recently are about Comodo’s AV Detection Engine but as @Melih has pointed out over and over again and I’ve explained here and there even to @New_Style_xd what do you do when just relying on signatures or behaviour for detection? Case in point this
MT - Self Made Fortran Malware topic where Comodo detected it first before Kaspersky, Eset or Checkpoint and therefore allowed to run wild on systems with that malware whereas even with the subsequent rehash of it, Comodo initially labelled it as Unknown and therefore Sandboxed but eventually detected it. Comodo protects you from any unknown or malicious file whether there is a signature for it or not.
There has been recent discussions about detecting dlls of trusted files but perhaps @Melih can provide the answer to that but as some have said, detecting dlls from trusted applications is practically impossible but that executable file would have to contain those dlls within the package in the first place so it’s likely to still be blocked/contained.