After issuing a cybersecurity advisory warning that APT hacker groups are purposefully targeting vulnerabilities in Fortinet FortiOS, the FBI now warned that after hacking a Fortinet appliance, state-sponsored attackers compromised the webpage of a US local government. 

Fortinet is a multinational security company based in Sunnyvale, California. It creates and sells cybersecurity solutions, which include hardware like firewalls as well as software and services like anti-virus protection, intrusion prevention systems, and endpoint security components.

"As of at least May 2021, an APT actor group almost certainly exploited a Fortigate appliance to access a web-server hosting the domain for a U.S. municipal government," the FBI's Cyber Division said in a TLP:WHITE flash alert published on 27th May. 

The advanced persistent threat (APT) actors moved laterally around the network after gaining access to the local government organization's server, creating new domain controller, server, and workstation user identities that looked exactly like existing ones. On compromised systems, attackers linked to this ongoing APT harmful activity have created 'WADGUtilityAccount' and 'elie' accounts, according to the FBI.

This APT organization will most likely utilize this access to capture and exfiltrate data from the victims' network, according to the FBI. "The APT actors are actively targeting a broad range of victims across multiple sectors, indicating the activity is focused on exploiting vulnerabilities rather than targeted at specific sectors," the FBI added.

Last month, the FBI and the CISA issued a warning about state-sponsored hacking groups gaining access to Fortinet equipment by exploiting FortiOS vulnerabilities CVE-2018-13379, CVE-2020-12812, and CVE-2019-5591. The threat actors are also scanning for CVE-2018-13379 vulnerable devices on ports 4443, 8443, and 10443, and enumerating servers that haven't been patched against CVE-2020-12812 and CVE-2019-5591. 

Once they've gained access to a vulnerable server, they'll use it in subsequent attacks aimed at critical infrastructure networks. "APT actors may use other CVEs or common exploitation techniques—such as spear-phishing—to gain access to critical infrastructure networks to pre-position for follow-on attacks," the two federal agencies said.

"APT actors have historically exploited critical vulnerabilities to conduct distributed denial-of-service (DDoS) attacks, ransomware attacks, structured query language (SQL) injection attacks, spear-phishing campaigns, website defacements, and disinformation campaigns." They further told.