Malicious hackers are taking advantage of commonly used enterprise remote access tools to break into retail point-of-sale (POS) systems and plant malware on them, the U.S. Department of Homeland Security warned Thursday.
In an advisory prepared jointly with the U.S. Secret Service, DHS said it has learned of attackers using publicly available scanning tools to locate businesses that use remote desktop applications. Such applications, from companies like Microsoft, Apple and LogMeIn allow workers, business partners, vendors and other third parties to access enterprise systems remotely.
Once the hackers locate a remote desktop app, they try and guess the user's login credentials using brute force methods. They then are able to infiltrate the enterprise network as an insider and eventually gain access to critical systems.
DHS investigations show that hackers have used the method successfully to infect POS systems at three retailers with a malware program dubbed "Backoff."
"At the time of discovery and analysis, the malware variants had low to zero percent anti-virus detection rates, which means that fully updated anti-virus engines on fully patched computers could not identify the malware as malicious," the DHS said.
Backoff is part of a family of POS malware hackers have been using to steal credit card and other data from payment systems.
Attacks involving remote access tools have gained attention in the months since the massive data breach at Target. Attackers broke into Target's POS systems via a remote access account belonging to a Heating, Ventilation and Air Conditioning (HVAC) company.
More recently, hackers broke into payment systems at several northwestern U.S. restaurants and food service companies via a remote access account belonging to one of their vendors.
In that incident, a LogMeIn account used by the vendor to remotely support and manage customer networks was breached and then used to plant data-stealing software on POS systems belonging to the vendor's customers.
In its alert, the DHS offered several high-level tips on how companies can mitigate the risk of being attacked.
Companies can configure their systems to lock a user account after a specific number of failed login attempts or after a specified period of time, the DHS noted. Limiting the number of users and workstations that can log in via remote access tools and segmenting public-facing systems from internal systems are critical to mitigating risk.
Point-to-point encryption and the use of smartcard-enabled POS systems can also make it harder for attackers to steal data, the DHS said.
The alert also listed several network security and incident response measures companies can take to avoid becoming victims of remote access attacks.
Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at @jaivijayan or subscribe to Jaikumar's RSS feed . His e-mail address is email@example.com.