Chinese state-backed hackers compromised at least 13 US gas pipeline operators in a spear-phishing and intrusion campaign conducted from December 2011 to 2013, according to a joint report from the Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA).

The previously unreported campaign targeted 23 U.S. oil and natural gas pipeline companies, of which “13 were confirmed compromises, 3 were near misses, and 7 had an unknown depth of intrusion.”

"The US government has attributed this activity to Chinese state-sponsored actors. CISA and the FBI assess that these actors were specifically targeting US pipeline infrastructure for the purpose of holding US pipeline infrastructure at risk," the two agencies said.

“Additionally, CISA and the FBI assess that this activity was ultimately intended to help China develop cyberattack capabilities against U.S. pipelines to physically damage pipelines or disrupt pipeline operations.”

According to the FBI and CISA, the hackers made no attempts to modify the pipeline operations of systems they accessed, instead they appear to have been more interested on collecting SCADA-related information, personnel lists, credentials, and system manuals.

While the security advisory does not identify threat actors behind this campaign, it provides Indicators of Compromise (IoCs) related to the intrusions.

The report comes merely a day after the US and its foreign allies accused the Chinese Ministry of State Security of a global hacking campaign, including a large-scale attack on Microsoft Exchange servers and other activity in cyberspace described as "irresponsible and destabilizing behavior”.