A group of hackers suspected to be linked to North Korea has attacked a U.S. government agency and researchers working on DPRK issues with a new type of malware, cybersecurity firm Palo Alto Networks said in a report issued late last month.

The group sent emails with six different Microsoft Word documents in Russian that contained malicious macros aiming to give attackers control over the recipients’ computers, the researchers explained in a blog post detailing the hacking campaign.

The malicious code, dubbed “CARROTBALL” and distributed by the “Konni” group of hackers, facilitates the download and installation of a backdoor that