Kaspersky Lab performed a forensic investigation into cybercriminal attacks targeting multiple ATMs around the world. During the course of this investigation, researchers discovered the Tyupkin malware used to infect ATMs and allow attackers to remove money via direct manipulation, stealing millions of dollars.
The criminals work in two stages. First, they gain physical access to the ATMs and insert a bootable CD to install the Tyupkin malware. After they reboot the system, the infected ATM is now under their control and the malware runs in an infinite loop waiting for a command. To make the scam harder to spot, the Tyupkin malware only accepts commands at specific times on Sunday and Monday nights. During those hours, the attackers are able to steal money from the infected machine.
Video footage obtained from security cameras of the infected ATMs showed the methodology used to access the cash from the machines. A unique digit combination based on random numbers is newly generated for every session. This ensures that no person outside the gang could accidentally profit from the fraud. Then the malicious operator receives instructions by phone from another member of the gang who knows the algorithm and is able to generate a session key based on the number shown. This ensures that the mules collecting the cash do not try to go it alone.
When the key is entered correctly, the ATM displays details of how much money is available in each cash cassette, inviting the operator to choose which cassette to rob. The ATM then dispenses 40 banknotes at a time from the chosen cassette.
The Tyupkin malware
At the request of a financial institution, Kaspersky Lab’s Global Research and Analysis Team performed a forensic investigation into this cyber-criminal attack. The malware identified and named by Kaspersky Lab as Backdoor.MSIL.Tyupkin, has so far been detected on ATMs in Latin America, Europe and Asia.
“Over the last few years, we have observed a major upswing in ATM attacks using skimming devices and malicious software. Now we are seeing the natural evolution of this threat with cyber-criminals moving up the chain and targeting financial institutions directly. This is done by infecting ATMs themselves or launching direct APT-style attacks against banks. The Tyupkin malware is an example of the attackers taking advantage of weaknesses in the ATM infrastructure,” said Vicente Diaz, principal security researcher at Kaspersky Lab. “We strongly advise banks to review the physical security of their ATMs and network infrastructure and consider investing in quality security solutions,” he added.
“Offenders are constantly identifying new ways to evolve their methodologies to commit crimes, and it is essential that we keep law enforcement in our member countries involved and informed about current trends and modus operandi,” said Sanjay Virmani, director of the INTERPOL Digital Crime Centre.
Kaspersky Lab recommends the following to banks in order to mitigate the risk:
- Review the physical security of all ATMs and consider investing in quality security solutions.
- Replace all locks and master keys on the upper hood of the ATM machines and ditch the defaults provided by the manufacturer.
- Install an alarm and ensure it is in good working order. The cyber-criminals behind Tyupkin only infected ATMs that had no security alarm installed.
- Change the default BIOS password.
- Ensure the machines have up-to-date antivirus protection.