Security researchers recently observed a malware campaign that leverages a particular type of USB drive to target specific Windows machines.

The threat group Tick may have exploited poor supply chain security to modify USB drives, according to a June 2018 report from Palo Alto Networks Unit 42. This possible attack is just the latest in a long line of malware campaigns targeting supply chains — a trend that can be largely attributed to the fact that many vendors don’t have proper security protocols in place.

What can organizations do to ensure their third-party suppliers are protected from vulnerabilities that might expose enterprise networks to malware?

Are Supply Chain Flaws to Blame for Tick Attacks?

The Tick group attempts to trick victims into installing a Trojanized version of a software that downloads SymonLoader malware onto machines running either Windows XP or Windows Server 2003, according to the report. Upon installation, the malware begins monitoring for a specific type of secure USB drive made by a South Korean defense company. If it detects this USB drive, SymonLoader extracts an unknown executable file from the device and runs it on the local disk.

The report noted that the Tick group likely incorporated a secure USB drive into its campaign to target air-gapped computers not connected to the web. Even so, the researchers admitted that they’re unsure how Tick compromised the USB drives in the first place.

“Because we do not have either a compromised USB drive or the unknown malicious file, we are also unable to determine how these USB drives have been compromised,” the report stated. “Specifically, we do not know if there has been a successful compromise in the supply chain making these devices, or if these have been compromised post-manufacturing and distributed using other means such as social engineering.”

How Can Companies Improve Supply Chain Security?

If the Tick group did indeed infect organizations through their supply chains, it would hardly be the first-time threat actors used this tactic. Last year, more than 2 million users who installed a security application were infected with a multistage malware attack that researchers believe originated in the provider’s supply chain.

According to F-Secure, threat groups have also used this tactic to prey on organizations operating industrial control systems (ICSs). When these threats are successful, it’s often because third-party suppliers and vendors fail to implement adequate security to protect connections to enterprise networks.

In fact, a July 2017 CybSafe report found one in seven small to midsize enterprises have no security protocols in place.

In light of these risks, IBM experts advise organizations to carefully review cloud configurations and ensure that all data accessible to third-party suppliers is protected with strong encryption. Security leaders should also ensure that enterprise password, patch management and data protection policies extend to all suppliers connecting to corporate networks and consider investing in data loss prevention (DLP), cloud access security broker (CASB) and security information and event management (SIEM) solutions to more closely monitor third-party access.

Sources: Palo Alto Networks, F-Secure, CybSafe