US-CERT: Critical infrastructure under persistent attack
- By Lauren C. Williams
Critical infrastructure systems and government networks have suffered a series of targeted attacks affecting domain controllers and file and email servers over the past five months or more, according to an advanced persistent threat activity alert from the U.S. Computer Emergency Readiness Team.
The Department of Homeland Security and FBI conducted the analysis, and they determined the attacks are part of an ongoing "multi-stage intrusion campaign" that targets "low security and small networks to gain access and move laterally to networks of major, high value asset owners within the energy sector," U.S. CERT said in its Oct. 20 alert. Networks spanning the aviation, manufacturing, nuclear and water sectors were affected.
Spearphishing emails from legitimate accounts that have been compromised are the primary mode of delivery. Attackers typically gain access through peripheral third-party organizations such as suppliers that tend to have less secure networks. Those networks then become "pivot points and malware repositories" for threat actors when attacking the intended victims. Once the intended victim's networks have been accessed, attackers implant remote control software on the systems with a focus on "identifying and browsing file servers," CERT wrote in its alert.
The analysis corroborated a Symantec's Dragonfly 2.0 report released in September. The report found that a sophisticated hacking group, Dragonfly 2.0, was behind potentially disruptive cyberattacks on energy sectors in Europe and North America in recent years.
DHS and Symantec previously told FCW's sibling publication GCN that the attacks weren't a public safety hazard and that a worst-case scenario would be if an attacker "successfully disrupted or destroyed systems that manage critical energy infrastructure."
A June report from Dragos Inc. not mentioned in the U.S. CERT alert found a similar malware threat targeting industrial control systems. That analysis showed that the malware dubbed CrashOverride was an improvement on previous frameworks developed by Dragonfly and BlackEnergy 2.