In May, security researchers at Proofpoint discovered a spam email campaign that was distributing a new banking Trojan named DanaBot. At the time it was thought that a single threat actor was using the DanaBot Trojan to target organizations in Australia to obtain online banking credentials.
That campaign has continued, but in addition, campaigns have been identified in Europe targeting customers of banks in Italy, Germany, Poland, Austria, and the UK. Then in late September, a further DanaBot Trojan campaign was conducted targeting U.S. banks.
The DanaBot Trojan is a modular malware written in Delphi that is capable of downloading additional components to add various different functions.
The malware is capable of taking screenshots, stealing form data, and logging keystrokes in order to obtain banking credentials. That information is sent back to the attackers’ C2 server and is subsequently used to steal money from corporate bank accounts.
An analysis of the malware and the geographical campaigns shows different IDs are used in the C2 communication headers. This strongly suggests that the campaigns in each region are being conducted by different individuals and that the DanaBot Trojan is being offered as malware-as-a-service. Each threat actor is responsible for running campaigns in a specific country or set of countries. Australia is the only country where there are two affiliates running campaigns. In total, there appears to currently be 9 individuals running distribution campaigns.
The country-specific campaigns are using different methods to distribute the malicious payload, which include the new Fallout exploit kit, web injects, and spam email. The latter is being used to distribute the Trojan in the United States.
The U.S. campaign uses a fax notice lure with the emails appearing to come from the eFax service. The messages look professional and are complete with appropriate formatting and logos. The emails contain a button that must be clicked to download the 3-page fax message.
Clicking on the button will download a Word document with a malicious macro which, if allowed to run, will launch a PowerShell script that downloads the Hancitor downloader. Hancitor will then download the Pony stealer and the DanaBot Trojan.
Proofpoint’s analysis of the malware revealed similarities with the ransomware families Reveton and CryptXXX, which suggests that DanaBot has been developed by the same group responsible for both of those ransomware threats.
The U.S. DanaBot campaign is targeting customers of various U.S. banks, including RBC Royal Bank, Royal Bank, TD Bank, Wells Fargo, Bank of America, and JP Morgan Chase. It is likely that the campaigns will spread to other countries as more threat actors are signed up to use the malware.
Preventing attacks requires defense in depth against each of the attack vectors. An advanced spam filter is required to block malspam. Users of Office 365 should increase protection with a third-party spam filter such as SpamTitan to provide better protection against this threat. To prevent web-based attacks, a web filtering solution should be used. WebTitan can block attempts by end users to visit websites known to contain exploit kits and IPs that have previously been used for malicious purposes.
End users should also trained never to open email attachments or click on hyperlinks in emails from unknown senders, or to enable macros on documents unless they are 100% certain that the files are genuine. Businesses in the United States should also consider warning their employees about fake eFax emails to raise awareness of the threat.