COATHANGER is a remote access tool (RAT) targeting FortiGate networking appliances. First used in 2023 in targeted intrusions against military and government entities in the Netherlands along with other victims, COATHANGER was disclosed in early 2024, with a high confidence assessment linking this malware to a state-sponsored entity in the People's Republic of China. COATHANGER is delivered after gaining access to a FortiGate device, with in-the-wild observations linked to exploitation of CVE-2022-42475.

The name COATHANGER is based on a unique string in the malware used to encrypt configuration files on disk: “She took his coat and hung it up”.