Malware authors are using an advanced toolset for industrial espionage, warned researchers at cybersecurity firm Kaspersky.

Kaspersky uncovered a series of highly targeted attacks against industrial holdings by advanced persistent threat (APT) actors.

These cybercriminals are using a toolset originally named MT3. Dubbed by Kaspersky as “MontysThree,” the tool uses “a variety of techniques to evade detection, including hosting its communications with the control server on public cloud services and hiding the main malicious module using steganography.”

The malware

MontysThree consists of four different modules. Initially, the cybercriminals spread the first loader using RAR SFX files which are self-extracted archives. These files are disguised to trick employers into downloading them. They contain names related to employees’ contact lists, technical documentation, and medical analysis results to trick employees as part of a common spear-phishing technique. The loader deploys a technique known as steganography to ensure that the malware remains undetected.

“Steganography is used by actors to hide the fact that data is being exchanged,” explained Kaspersky.

The primary malware in the case of MontysThree is disguised as a bitmap (a format for storing digital images) file.

“If the right command is inputted, the loader will use a custom-made algorithm to decrypt the content from the pixel array and run the malicious payload,” the report said.

MontysThree is designed to specifically target Microsoft and Adobe Acrobat documents, Kaspersky said. The malware can enable attackers to capture screenshots and gather information about the victim’s network settings, hostname, etc.

“The information collected and other communications with the control server are then hosted on public cloud services like Google, Microsoft, and Dropbox. This makes the communication traffic difficult to detect as malicious, and because no antivirus blocks these services, it ensures the control server can execute commands uninterrupted,” explained Kaspersky.

Threat profile

According to Kaspersky, the campaign is far rarer as compared to APT campaigns against diplomats and other high-profile political actors.

“ Far more rare are targeted espionage campaigns against industrial entities—but, like any other attacks against industries, they can have devastating consequences for the business,” Kaspersky said.

“MontysThree is interesting not just because of the fact that it’s targeting industrial holdings, but because of the combination of sophisticated and somewhat “amateurish” TTPs,” said Denis Legezo, senior security researcher with Kaspersky’s Global Research and Analysis Team.

“However, they use strong cryptographic standards and there are indeed some tech-savvy decisions made, including the custom steganography. Perhaps most importantly, it’s clear that the attackers have put significant effort into developing the MontysThree toolset, suggesting they are determined in their aims—and that this is not meant to be a short-lived campaign,” Legezo added.