Point-of-sale malware dubbed ChewBacca has hit dozens of small retailers in 11 countries as far apart as the US, Russia, Canada and Australia.
Researchers at RSA Security have put the ChewBacca Trojan under microscope revealing much more information about a strain of malware targeted at retailers that, whilst not new for security researchers, has escaped widespread notice to date.
ChewBacca features simple keylogging and memory-scraping functionality. The malware earns its moniker from a server login image featuring the heroic Wookie from the Star Wars films. The malware uses the darknet as a communications channel, a blog post by a security researcher at RSA explains.
The malware has logged track 1 and 2 payment cards data scraped from infected PoS systems, and most of the victims are located in the United States. However, despite the obvious similarities, the malware is not related to the modified version of BlackPOS linked to recent mega-heists at shopping giant Target and luxury retailer Neiman Marcus.
"RSA observed that communication is handled through the TOR network, concealing the real IP address of the Command and Control (C&C) server(s), encrypting traffic, and avoiding network-level detection," writes Yotam Gottesman, a senior security researcher in RSA's FirstWatch team.
"The server address uses the pseudo-TLD “.onion” that is not resolvable outside of a Tor network and requires a Tor proxy app which is installed by the bot on the infected machine. The ChewBacca Trojan appears to be a simple piece of malware that, despite its lack of sophistication and defense mechanisms, succeeded in stealing payment card information from several dozen retailers around the world in a little more than two months."
Chewbacca has reportedly been abused in stealing 49,000 payment card details from 45 retailers in 11 countries worldwide. All this is, of course, small beer compared to the 40 million consumer credit and debit cards potentially lifted by the Target breach but still bad news.
And ChewBacca is but one item in a menagerie of retail malware that also include Dexter and Alina.
Richard Moulds, VP product strategy at Thales e-Security, said the spread of malware was unsurprising, given the woeful state of security in retail environments. "In-store point of sale terminals are particularly vulnerable because they handle highly sensitive card holder data, they exist in large numbers so are hard to manage and yet are in notoriously insecure places – the retail store," Moulds explained.
"We already have a solution for protecting PINs and it works just fine, we rarely see stories of stolen PINs. PINs are encrypted directly in the card reader itself by physically hardened circuitry as soon as they are entered by the shopper. "
Moulds described the point of sale terminal as a weak link in a chain that can strengthened through the use of encryption technology.
"They [PINs] are only decrypted when absolutely necessary and only in similarly hardened devices called hardware security modules (HSMs) - everything in between, including the point of sale terminal, only sees scrambled data which is useless to an attacker."
"We should extend this approach to cover all card holder data. Encrypt or tokenise cardholder data at the point of capture and decrypt only on a need to know basis and only in trusted environments," he added. ®