ESET researchers have discovered and analyzed an ongoing malicious campaign, which distributes a backdoor via torrents, using Korean television content (movies, shows) and often games as bait.
The backdoor has spread through torrent sites in South Korea and China. The malware allows the attacker to connect the compromised computer to a botnet and remotely control it.
This malware is a modified version of GoBot2, a publicly available backdoor. The source code modifications mainly concern escape techniques specifically for use in South Korea. As the campaign clearly targets that country, ESET has named GoBotKR the specific version of Win64 / GoBot2. According to ESET telemetry, GoBotKR is active by 2018. South Korea is the country with the most attacks (80% of detections), followed by China (10%) and Taiwan (5%).
"The cybercriminals behind this campaign are trying to trick users into running the malicious software by placing traps in the content of torrents with malicious files that have misleading file names, extensions and icons,” says ESET researcher Zuzana Hromcova, who analyzed the malware.
No malice will arise energy directly by opening the MP4 file. The catch here is that the MP4 file is often hidden in a different directory, and users may encounter the malicious file impersonating it first.
According to ESET, the malware is not particularly technically complex. However, the cybercriminals behind GoBotKR are building one network by bots, which can then be used to perform various kinds of DDoS attacks. Therefore, after its execution, GoBotKR first collects system information about the compromised computer, such as network settings, OS version information, CPU and GPU.
Specifically, it collects a list of installed antivirus products. This information is sent to a C&C server, which helps intruders determine which bots can be used in the respective attacks. "All the C&C servers found through the malware samples analyzed were found to be hosted in South Korea and registered by the same person," Hromcova explained in her research.
The bot has many possibilities, such as enabling abuse of the compromised computer, or giving botnet operators the ability to further control or expand the botnet. It also allows to avoid detection and hide from the user.
Among other supported commands are the ability to direct a DDoS attack to specific victims, copy the malware to attached removable media or public cloud storage service folders (Dropbox, OneDrive, Google Drive), as well as embedding torrents with the malicious file as a means to further expand the botnet.
In terms of research, GoBotKR is particularly interested in its escape techniques, which have been adapted to target South Korea. Specifically, malware scans processes running on the compromised system to detect specific antivirus products, including the products of a South Korean security solution company.
If any of the products are found, they are terminated. Another escape technique detects system-running analytics tools, again targeting the same South Korean security firm. In the third avoidance technique, the intruders misused legitimate South Korean electronic platforms to determine the victim's IP address.
"Overall, the modifications show us that the attackers are adapting the malware to a specific audience while also making extra efforts to prevent it from being detected," Hromcova concludes.
More details about GoBotKR and its features can be found in the ESET blogpost «Malicious campaign targets South Korean users with backdoor-laced torrents"At WeLiveSecurity.com.
______________
- Cloudflare what the end of 8chan support for pirate sites means
- Watch List ready European piracy watch list ready
- Online Piracy: The story of piracy before the World Wide Web
