F-Secure Virus Descriptions : Padania

Padania is a harmless memory resident Win95 virus. It stays resident in the Windows memory, hooks system IFS API calls, intercepts EXE file opening and then writes itself to the end of the file and modifies file's header to get control when infected programs are executed. A short virus entry code is also written into file's PE header.

The virus infects files in two ways depending on the file's structure. If the last section of the file is relocations ".reloc" section, the virus just overwrites it and erases relocation info in the PE header. Otherwise the virus adds one new section to the end of the file and writes its code to there.

To get control when infected file is run the virus also uses two ways: it either modifies the program's startup address, or patches the program's code with JMP_Virus instruction. In latter case the virus does not receive control immediately when an infected program is run, but only in case patched program's branch gets control.

To install its hooker into the Ring0 (VxD) Windows memory the virus uses the trick similar to "Win95.MarkJ" virus. It patches the PE sections so, that Windows95 loads virus code into the VMM Ring0 area instead of standard application's memory.

The virus does not manifest itself in any way. It contains the text strings:

 Padania_Libera
 by -b0z0/iKX-
 Padania