Kaspersky TDSSKiller for Windows

Free tools for removing TDSS and similar hidden malware

Malicious software that burrows into a system and hides itself — known as a rootkit — poses a different class of threat than ordinary viruses. One recent example, often called TDSS, modifies low-level components of an operating system so its files and processes remain invisible to many protection programs. Because it can mask its presence and interfere with other security tools, TDSS requires specialized removal utilities.

Why rootkits are harder to detect

Typical anti‑malware solutions scan files, running processes, and known signatures to find threats. A rootkit changes how the system reports that information, which can prevent scanners from seeing infected files or processes at all. In some cases the rootkit even damages or disables security software, making automatic cleanup difficult.

A targeted solution: Kaspersky TDSSKiller

Kaspersky’s TDSSKiller is a free utility designed specifically to find and remove TDSS-style rootkits. The current release can be launched on many compromised machines and will search for the hidden components these rootkits install. Users with moderate technical familiarity will find it straightforward to run; earlier releases sometimes failed on heavily infected systems, but Kaspersky has addressed those issues in newer builds.

How to run TDSSKiller (basic steps)

• Download the tool from a trusted source and save it to a removable drive if the PC is unstable.
• Boot into Safe Mode if the system is severely compromised and regular startup is unreliable.
• Launch the scanner, allow it to inspect system areas, and follow prompts to quarantine or delete identified items.
• Reboot after the cleanup and re-scan to verify the system is clean.

Other utilities worth trying

• Malwarebytes (well‑known general malware cleaner that can complement a rootkit scan)
• HijackThis (an advanced diagnostics tool useful for manually inspecting and cleaning persistent entries)
• A bootable rescue disk from a reputable vendor (useful when the OS will not start)
• Specialized rootkit scanners and removal tools from major security vendors

Best practices after removal

After removing a rootkit, update the operating system and all applications, change important passwords, and back up essential data. Consider running an additional full system scan with a different anti‑malware product to confirm no remnants remain. If the infection was deep or sensitive data may have been exposed, a clean OS reinstall is the safest option.