Dropper-for-Hire – Hackers Using a Single Malware to Drop 6 Different Malware in Targeted Systems

Researchers observed a new malware campaign under a dropper-for-hire method that drops 6 different malware to attack the targeted victims and perform a variety of malicious activities.

Nowadays malware authors collaborative with other threat actors to develop sophisticated malware become increasingly common.

In this case, dropper and the campaign it is associated with revealed involves multiple types of malware, and it is referred as a “Hornet’s Nest”.

The malware campaign includes multiple types of info-stealers, backdoors, a file-less crypto-currency stealer built into the dropper, and occasionally a crypto-miner as well. 

Legion Loader

Researchers observed the dropper with the name of “Legion Loader” through various network intrusion and emerging-threats rule-sets.

Malware author-written Legion loader in MS Visual C++ 8 and is believed to be written by Russian speaking developer.

Legion loader developed with a variety of features including VM/Sandbox (VMware, VBOX, etc.) and research-tool evasions (Common debuggers, SysInternals utilities,Wireshark, PETools, etc.), in many cases it lacks string obfuscation which allows for fairly straightforward analysis. Deep instinct said via a blog post.

Once the Legion Loader dropped and running in the targeted system, it connects to the command & control server for further command and it terminates itself if it will not receive any expected response.

Upon the successful connection, it will proceed to download and execute 2-3 hard-coded payloads from C2 server.

Legion Loader targeted at both the United States and Europe, is intended to deliver 2-3 additional malware executables and features a built-in file-less crypto-currency stealer and browser-credential harvester.

“Legion Loader is, as mentioned above, very aptly named; and is a classic case-in-point of how even a relatively low-sophistication malware can become a security nightmare for an organization, employing more advanced file-less techniques and delivering a myriad of follow-up malware ranging for info-stealers and credential harvesters to crypto-miners and backdoors.” Researchers said.

You can find the complete Indicators of Compromise here.