New York, NY, United States

A new botnet called TDL-4 might be indestructible, according to security researchers at Kaspersky Lab.

Researchers say about 4.5 million PCs have become infected with TDL-4 over the past three months.

Botnets are collections of infected computers that cybercriminals can control to launch attacks on other computers and computer systems.

TDL targets Windows PCs. It is hard to detect and stop because it uses code that hijacks a PC and hides in places that security software does not usually inspect. TDL botnets are controlled by a custom made encryption created by the cybercriminals who created botnets.

The original TDL malware appeared in 2008. Over the years it has been modified and researchers dubbed the latest version TDL-4 because it is the fourth generation of botnets.

Researchers say that TDL-4 is a significant improvement over its predecessors becuas it is has defenses against attacks and security software.

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