Hackers are extorting vast sums of money from unwary web users, using ransomware posing as the US Department of Homeland Security (DHS).
The US Computer Emergency Response Team (CERT) reported unearthing the ransomware, warning that one variant has advanced webcam hijacking powers.
"US-CERT has received reports of increased activity concerning an apparently DHS-themed ransomware malware infection occurring in the wild. Users who are being targeted by the ransomware receive a message claiming that use of their computer has been suspended and that the user must pay a fine to unblock it," read the CERT alert.
"One iteration of this malware also takes a webcam (if available) photo or video of a recipient and posts it in a pop-up to add to the appearance of legitimacy. The ransomware falsely claims to be from the US Department of Homeland Security and the National Cyber Security Division."
The CERT team said victims of the scam should not pay the blackmailers, and should instead contact a reputable security provider to remove the malware.
"Users who are infected with the malware should consult with a reputable security expert to assist in removing the malware, or perform a clean reinstallation of their OS after formatting their computer's hard drive. US-CERT and DHS encourage users and administrators not to pay the perpetrators and to report the incident to the FBI at the Internet Crime Complaint Center (IC3)."
The DHS ransomware is one of many new types of malware discovered masquerading as a law enforcement or government agency.
Within the UK a ransomware locking computers and displaying a bogus message claiming to come from the Serious Organised Crime Agency (SOCA) was uncovered targeting British web users.