Cyber-attackers targeting transaction data increasingly use software that monitors memory for unencrypted card numbers and account information.
Security professionals are focusing on the tools that attackers use to steal the credit card data and account information from point-of-sale (POS) terminals and computerized cash registers as the likely source of massive breaches at retailers Target and Neiman Marcus.
The most probable suspect is software known as a random access memory, or RAM, scraper, which steals data in its unencrypted form from the main memory of an infected computer.
While neither Target nor Neiman Marcus have disclosed what tools the attackers used, security experts suspect that POS terminals at both retail chains had been compromised with scrapers, which then stole credit card data and other account information. Reuters first reported
the link Jan. 12.
"They are grabbing at the stage before it is encrypted," Chester Wisniewski, senior security advisor at Sophos, told eWEEK.
"They are doing the same thing that the NSA does. You read it before it is encrypted or after it is decrypted, then you don't have to break the encryption."
On Jan. 11 Neiman Marcus confirmed
that online thieves had breached its computer systems. The acknowledgement followed Target's admission in December that online thieves stole more than 40 million credit card records and 70 million other account records containing sensitive data during a data breach that started at the big-box store chain on Nov. 29, also known as Black Friday. Both attacks were first reported by security journalist and researcher Brian Krebs.
Target apologized to its customers on Jan. 13, as it kicked off a public relations campaign to undo the damage done to the company by the 19-day attack. Neiman Marcus made its own short apology on Jan. 11.
"The security of our customers' information is always a priority, and we sincerely regret any inconvenience," the official Neiman Marcus Twitter account stated on Jan. 11. "We are taking steps, where possible, to notify customers whose cards we know were used fraudulently after purchasing at our stores."
While RAM scrapers are a key tool used in the attacks, the technology is not new. In 2009, Verizon flagged scrapers as an emerging threat, even though they only accounted for 4 percent of the cases in its data set at the time. Current versions of RAM scrapers include a malware threat alternatively known as Trackr and Alina, which have targeted the retail, service, health care, food services, education, hotel and tourism industries.
Credit card issuer Visa posted alerts in April
2013, warning that attackers had focused on grocery stores and retail chains with the malware.
"The malware is configured to 'hook' into payment application binaries," the company stated in its updates. "These binaries are responsible for processing authorization data, which includes the full magnetic stripe data."
While past RAM scrapers have been fairly simple, more modern versions are getting sophisticated. The programs are looking for a wider variety of data and taking steps to hide their tracks, such as encrypting stolen data, Sophos' Wisniewski said. In addition, attackers have added legitimate-sounding file names to deceive victims and linked the code using botnet functionality, according to a blog post
published by Sophos in July 2013.
"The attackers are getting much smarter," said Wisniewski.