While not particularly sophisticated, this malware is made to take different pieces of data from infected devices that can be used as a foundation for more attacks.

The ThirdEye 

The investigation on the infostealer began when the FortiGuard Lab researchers noticed an archive file named “Табель учета рабочего времени.zip” (English trans. “time sheet”). The zip file included two files immediately identified as “up to no good.”

Both files contain a double extension (.exe followed by a different document-related extension). One of the files is "CMK равила oормлени олнин листов.pdf.exe," which is an executable rather than a document and is labeled "QMS Rules for issuing sick leave" in English. f6e6d44137cb5fcee20bcde0a162768dadbb84a09cc680732d9e23ccd2e79494 is the file's SHA2 hash value.

The ThirdEye info stealer has comparatively simpler functionality. It contains a variety of system information based on compromised machines, like BIOS and hardware data. Additionally, it lists ongoing processes, folders and files, and network data. All of this information is gathered by the malware once it has been run, and it then sends it to its command-and-control (C2) server, which is located at (hxxp://shlalala[.]ru/general/ch3ckState). As compared to other infostealers, this one does nothing else.

An interesting string sequence unique to the ThirdEye infostealer family is the “3rd_eye”, which it decrypts and combines with another hash value to identify itself to the C2.

The second file in the archive is the “Табель учета рабочего времени.xls.exe”, which has the same name as its parent file. This file is a variant of the ThirdEye infostealer, created to achieve the same functions as f6e6d44137cb5fcee20bcde0a162768dadbb84a09cc680732d9e23ccd2e79494.

While there is no substantial evidence that could confirm that the ThirdEye infostealer was used in attacks, the malware however is created to steal valuable information from compromised machines, in order to have a better understanding of potential targets, and narrowing them down further. Moreover, there are speculations that the info stealer’s victims will be subject to future cyberattacks.

Since ThirdEye is not yet under the ‘severe’ radar, the FortiGuard investigation found that the threat actors involved have put efforts into strengthening the infostealer, such as recent samples collecting more system information compared to older variants, and it is anticipated to improve further.