Mobile Banking Trojans Targeting Crypto-Currencies
6.3.2018 securityweek Mobil  Android

Mobile malware is now targeting crypto-currencies with the intent of stealing victims’ funds, IBM says.

The immediate result of the massive increase in value that crypto-currencies have registered over the past year was the growth of malicious attacks attempting to steal coins from unsuspecting users. While most of these assaults involved PC malware so far, recent incidents have shown that mobile threats are picking up the pace as well.

Several weeks ago, IBM observed that the TrickBot Trojan was using webinjections to steal virtual coins from its victims by replacing legitimate addresses with those of the attacker. Working in a similar manner, mobile malware is now using screen overlays to trick victims into sending funds to the attacker instead, IBM's security researchers discovered.

According to IBM, mobile malware targeting crypto-coins usually leverages malicious miners to collect coins, but the practice isn’t that profitable, given the limited processing power a mobile device has. Furthermore, users are more likely to discover a mining operation on a mobile device when observing overheating, low performance and faster battery drain.

“Crooks operating mobile banking Trojans don’t install miners on the device. Rather, they typically steal existing coins from unsuspecting owners using mobile malware that creates the same effect as webinjections: cybercriminals trick users with fake on-screen information, steal their access credentials and take over accounts to empty coins into their own wallets,” IBM notes.

Some of the mobile malware families capable of detecting the application opened on a mobile device include ExoBot, BankBot, Marcher, and Mazar. Based on the launched application, these Trojans can display a hardcoded or dynamically fetched overlay and hide the legitimate app screen behind a fake one.

Thus, users end up revealing their credentials to the malware operators, which can then abuse them to access the victim’s account. If a second-factor authorization is required, the malware can hijack it from the compromised device without alerting the victim.

Usually employed in attacks targeting bank accounts, the method has been adapted for the theft of crypto-coins as well, the researchers discovered. Trojans such as BankBot and Marcher have been already packed with the necessary functionality to overlay a fake screen when the user opens relevant wallet apps.

The malware, IBM says, targets multiple virtual currencies, including Bitcoin, Bitcoin Cash, Ethereum, Litecoin, Monero, and other. Although basic-looking, the overlay screens are convincing and can trick users into unknowingly sending their access credentials to an attacker.

“The mobile malware arena already strives to emulate the success of PC banking Trojans and facilitate cross-channel fraud and identity theft. Cryptocurrency is just another target for malware operators looking to get in on the action. Given the rapid evolution of this threat, organizations should invest in mobile threat protection tools to minimize the risk posed by mobile banking Trojans,” IBM concludes.