Malware Analysis - Dark Comet RAT
A Remote Administration Tool (otherwise known as a RAT) is a piece of software designed to provide full access to remote clients. Capabilities often include keystroke logging, file system access and remote control; including control of devices such as microphones and webcams. RATs are designed as legitimate administrative tools, yet due to their extensive capabilities are often seen used with malicious intent.
When a RAT is identified as the payload in a malicious infection, typical malware analysis will resolve all the capabilities being provided to the attacker. However, the attacker may not be using all the capabilities provided; they may only be using the keylogging facility, or using the backdoor to install further tools onto the infected host. To make a full impact assessment, this detail is necessary and may only be available through analysis of the commands sent to the host by the attacker. However, access to the command and control traffic is limited as most RATs implement encryption or obfuscation to hide data sent over the network.
In this blog post I will take a look at a RAT called Dark Comet. I will run through the capabilities provided by the tool, examine the associated network traffic, identify the encryption algorithm and show how the key can be identified with a little analysis of an infected host.