It is time to publish a plugin I wrote some time ago, but it is still really useful, I’m planning to release an updated version in the near future :)

immSignSrch is a signatures scanner plugin for Immunity Debugger developed upon Luigi Auriemma’s signSrch.

Features:

Fast search engine;
It can recognize:
-  tons of compression, multimedia and encryption algorithms;
-  many other things (like known strings and anti-debugging code).
Signatures DB automatically updatable from the program itself and editable by hand.

Usage:

From the command line (ALT + F1) type: !iss -h

Download:

Latest release of immSignSrch is available here.

Have fun :)