TeamSpy, the data-stealing malware that was associated with a decade-long cyber-espionage operation several years ago, has resurfaced in a new attack campaign, Heimdal Security researchers warn.
The malware, designed to provide its operators with full access to the compromised machines, was used in an information gathering operation that focused mainly on ordinary people, though some victims were found to be high profile industrial, research, or diplomatic targets. The malware was abusing the legitimate TeamViewer remote access tool for its nefarious operations, researchers discovered.
The newly observed attack relies on social engineering to trick potential victims into installing TeamSpy onto their computers. The malware is being distributed via spam emails that contain a malicious ZIP attachment designed to drop an infected DLL (MSIMG32.dll) on the target machine. Two other files are also downloaded onto the computer: 324.bat and 324.exe.
The same as other TeamViewer-abusing malware, the malicious app leverages DLL hijacking to abuse the legitimate software for its nefarious operations. TeamSpy includes various components of the legitimate program, such as a TeamViewer VPN and a keylogger. Upon installation, it kills a series of Windows processes to install these components and launch them.
Simultaneously, the malware copies logs to a text file and writes all usernames and passwords it can find to it. The file is then sent to the command and control (C&C) server.
The final goal of the attack, however, is to gain complete control of the infected PC and to gather confidential information from it while keeping a low profile to avoid alerting the user. For that, the malware downloads additional components, including the TeamViewer application.
“Given how the TeamSpy infection happens, it is clear that a TeamViewer session started by the attackers will be invisible to the victim. This can lead to numerous forms of abuse against the services that the logged in user runs on his/her computer,” Heimdal Security’s Andra Zaharia notes. What’s more, the attack can circumvent two-factor authentication, she says.
The newly observed payload has a low detection rate at the moment and users are advised to carefully analyze all unwanted emails and to avoid downloading attachments from unknown senders. “Malware can disguise itself in many forms on the web, and all it takes is one click to trigger an infection,” Zaharia concludes.
Related: Mitigating TeamSpy Cyber-espionage Attacks

More from Ionut Arghire
- Google Temporarily Offering $180,000 for Full Chain Chrome Exploit
- Toyota Discloses New Data Breach Involving Vehicle, Customer Information
- Adobe Inviting Researchers to Private Bug Bounty Program
- Critical Vulnerabilities Found in Faronics Education Software
- Chrome 114 Released With 18 Security Fixes
- Spyware Found in Google Play Apps With Over 420 Million Downloads
- Millions of WordPress Sites Patched Against Critical Jetpack Vulnerability
- PyPI Enforcing 2FA for All Project Maintainers to Boost Security
Latest News
- Google Temporarily Offering $180,000 for Full Chain Chrome Exploit
- Russia Blames US Intelligence for iOS Zero-Click Attacks
- Toyota Discloses New Data Breach Involving Vehicle, Customer Information
- Cisco Acquiring Armorblox for Predictive and Generative AI Technology
- Moxa Patches MXsecurity Vulnerabilities That Could Be Exploited in OT Attacks
- Amazon Settles Ring Customer Spying Complaint
- Organizations Warned of Salesforce ‘Ghost Sites’ Exposing Sensitive Information
- Adobe Inviting Researchers to Private Bug Bounty Program
