ISFB
Intelligence Profile
2006 Gozi v1.0, Gozi CRM, CRM, Papras
2010 Gozi v2.0, Gozi ISFB, ISFB, Pandemyia(*)
In September 2010, the source code of a particular Gozi CRM dll version was leaked. This led to two main branches: one became known as Gozi Prinimalka, which was merge with Pony and became Vawtrak/Neverquest.
The other branch became known as Gozi ISFB, or ISFB in short. Webinject functionality was added to this version.
There is one panel which often was used in combination with ISFB: IAP. The panel's login page comes with the title 'Login - IAP'. The body contains 'AUTHORIZATION', 'Name:', 'Password:' and a single button 'Sign in' in a minimal design. Often, the panel is directly accessible by entering the C2 IP address in a browser. But there are ISFB versions which are not directly using IAP. The bot accesses a gate, which is called the 'Dreambot' gate. See win.dreambot for further information.
ISFB often was protected by Rovnix. This led to a further complication in the naming scheme - many companies started to call ISFB Rovnix. Because the signatures started to look for Rovnix, other trojans protected by Rovnix (in particular ReactorBot and Rerdom) sometimes got wrongly labelled.
In April 2016 a combination of Gozi ISFB and Nymaim was detected. This breed became known as GozNym. The merge uses a shellcode-like version of Gozi ISFB, that needs Nymaim to run. The C2 communication is performed by Nymaim.
See win.gozi for additional historical information.
Threat Analysis
ISFB is a malware family tracked by threat intelligence researchers and catalogued in the Malpedia dataset. It represents a distinct malicious software lineage with identifiable code characteristics, behaviors, and victimology.