Brazilian Banking Trojan Which Delivering under the name vm.png through Spam Email Champaign Allow to Hijack Victims Device and attackers send himself Victims Funds.
An old banking fraud toolkit first discovered by IBM Trusteer in January 2015 has reared its ugly head again, this time in the form of a trojan called Boleto which uses overlay technique to dupe consumers of their banking details and even money.
The user-friendly Trojan is available in the Brazilian black market and can be used by hackers with minimal technical skills but is almost as deadly as some of the popular tools like Trickbot or those offered by Zeus.
While the aforementioned tools use phishing attacks, Boleto uses malware sent through email attachments to install Java code using a JAR file.
How This Banking Trojan works
Upon opening a malicious mail infected by the malware, the user is forced to install Java code using a JAR file.
The JAR file contains an executable VMware file called vprintproxy.exe(hidden under a png file) which is a legitimate file signed by VMware.
Using DLL hijacking techniques the malicious code is then stored in vmwarebase.dll, thus going under the scanner of an anti-virus or anti-malware scanner.
Malware Working Function
Once in, as most malware do, it waits and bides its time till the end user logs into his/her banking site.
Once logged in, the malware sends an SMS to the remote attacker and a pop-ups an authentic looking overlay screen on top the user’s browser.
- Replacing current screen with a provided image
- Changing current system cursor
- Autorun registry persistence establishment
- Shutting down system utilities (such as taskmgr, dwm, regedit etc.)
- Invoking system reboot
- File\dir deletion functions
The Malware Module Interconnection:
The purpose of the overlay is to distract the user while underneath the overlay, the attacker makes merry with the logged in user information and conduct transactions as his/her will usually involving transferring money, stealing information etc.
This Trojan Kill some unwanted Process such as taskmgr.exe,msconfig.exe, regedit.exe, ccleaner.exe / ccleaner64.exe, dwm.exe (for Windows 7 only) iexplore.exe,iexplore.exe,iexplore.exe, firefox.exe,chrome.exe, opera.exe, opera.exe,safari.exe, NetExpress50.exe AplicativoBradesco.exe
Due to its sheer brilliance, stopping this fraud would require in addition to updated signature patterns for an anti-malware scanner, detection of remote access tools, checking for out of the ordinary browser behaviors.
The end user has to be educated on how to deal with the threat with the onus lying on the banks also to educate and inform the users that should such overlays happen during a logged in session, to immediately log out and alert the relevant authorities.