Canadian CSOs in the retail sector need to be aware of a warning issued Friday by US-CERT that the Backoff point of sale malware continues to be a threat in the sector.
Seven PoS system providers/vendors have confirmed that they have had multiple clients affected over the past year, the advisory said with the U.S. Secret Service currently estimating that over 1,000 U.S. businesses are affected.
“Recent investigations revealed that malicious actors are using publicly available tools to locate businesses that use remote desktop applications. Remote desktop solutions like Microsoft’s Remote Desktop, Apple Remote Desktop, Chrome Remote Desktop, Splashtop 2, Pulseway and LogMeIn offer the convenience and efficiency of connecting to a computer from a remote location,” says the advisory.
“Once these applications are located, the suspects attempted to brute force the login feature of the remote desktop solution. After gaining access to what was often administrator or privileged access accounts, the suspects were then able to deploy the point-of-sale (PoS) malware and subsequently exfiltrate consumer payment data via an encrypted POST request.”
The most publicized attack was on Target stores in the U.S. last fall. There haven’t been recent reports of exploits in this country, but in the last few weeks the U.S. supermarket chain SuperValu as well as a number of franchise outlets of courier UPS were hit.
There are several variations, several of which have an explorer.net malicious stub injection component and the ability to log keystrokes. Once infected the malware scrapes memory for track data.
US-CERT alert (see the link at the top) recommends some 26 defence strategies for this another other intrusions, some of which should be followed by any organization: For example, limit the number of users and workstations that can log in using Remote Desktop, use firewalls to restrict access to remote desktop listening ports, and change the default Remote Desktop listening port. Requiring two factor authentication for remote desktop access and when accessing payment processing networks — even if an VPN is used — helps mitigate keylogger or credential dumping attacks.
For improved POS security, hardware-based point to point encryption is recommended, two-factor authentication for security solutions and – perhaps especially important now — monitor logs daily.