Technology

Tropic Trooper (also known as KeyBoy and Pirate Panda) is an APT group active since 2011. This group has traditionally targeted sectors such as government, healthcare, transportation and high-tech industries in Taiwan, the Philippines and Hong Kong. Our recent investigation has revealed that in 2024 they conducted persistent campaigns targeting a government entity in the Middle East, starting in June 2023.

Sighting this group’s TTPs in critical governmental entities in the Middle East, particularly those related to human rights studies, marks a new strategic move for them. This can help the threat intelligence community better understand the motives of this threat actor.

The infection came to our attention in June 2024, when our telemetry gave recurring alerts for a new China Chopper web shell variant (used by many Chinese-speaking actors), which was found on a public web server. The server was hosting an open-source content management system (CMS) called Umbraco, written in C#. The observed web shell component was compiled as a .NET module of Umbraco CMS.

In our subsequent investigation, we looked for more suspicious detections on this public server and identified multiple malware sets. These include post-exploitation tools, which, we assess with medium confidence, are related to and leveraged in this intrusion.

Furthermore, we identified new DLL search-order hijacking implants that are loaded from a legitimate vulnerable executable as it lacks the full path specification to the DLL it needs. This attack chain was attempting to load the Crowdoor loader, which is half-named after the SparrowDoor backdoor, detailed by ESET. During the attack, the security agent blocked the first Crowdoor loader, prompting the attackers to switch to a new, previously unreported variant, with almost the same impact.