I've downloaded a certain DLL from the web and then uploaded it to Jotti's virus scan. All of those engines reported Found nothing. Nothing.
Can there still be some sort of security issue with this file or am I pretty safe that this file's ok?
What else should I consider to check its bad intentions?
Yes it's a patch for some original DLL. SLL is a compiled non-managed code. It differs from the original in a bit more than 2k bytes. I thought of decompiling it and compare source code of both to see differences, but since it's unmanaged DLL I'm pretty much done.