North Korean cybercriminals are using a new malware to secretly gain control of victim’s computers in a “sophisticated and stealthy” campaign targeting Southeast Asian countries, a U.S. cybersecurity firm reported on Thursday.

Securonix said in a report that the threat group APT37, also known as Scarcruft and Reaper, used phishing emails to deliver a custom backdoor granting attackers “full access” to the compromised machine.

The backdoor, dubbed “VeilShell” by researchers, comes with a wide range of Remote Access Trojan (RAT) capabilities including data extraction and task creation or manipulation, according to the report