DanaBot Banking Trojan came out with new features which harvest email addresses from the victim’s mailbox and send out spam emails.
This Trojan turned out to be the latest example for the malware which focused on stealing useful information rather than demanding ransom from victims. The campaign primarily focuses on corporate and public administration emails.
DanaBot Banking Trojan Gets into Email Spam
In September 2018, ESET researchers noticed that the trojan used web injections against users of an unnamed Italian mail service.
An investigation has shown that malicious javascript embedded in the pages of webmail services fall into two categories.
First, DanaBot collects email addresses from the victim’s existing mailboxes and sends all the collected information to the C&C server.
Secondly, if the mail service is based on Open-Xchange, the Trojan injects a Javascript that covertly sends spam from the victim mailbox.
The mail attachment includes ZIP file which contains a decoy PDF document and a malicious VBS file, Once the VBS file executes, it downloads more malware using PowerShell cmd.
This trojan includes a significant amount of junk code including instructions, conditional statements, and loops.
To prevent researchers and automated tools from easily understanding the code’s purpose, the trojan uses Windows API function hashing and encrypted strings.
ESET Researchers found that the links between DanaBot and GootKit. Matches were also noticed in the subnet of C&C servers and the strange similarity of domains used by the attacker.
Researchers said DanaBot uses exactly the same scripts that used in BackSwap trojan including the namings and locations of scripts in the server.
