Viruses and Malware

Joke program

A joke program is a virus-like program that often manipulates the appearance of things on an endpoint monitor.

Trojan horse program

A Trojan horse is an executable program that does not replicate but instead resides on endpoints to perform malicious acts, such as opening ports for hackers to enter. This program often uses Trojan ports to gain access to endpoints. An application that claims to rid an endpoint of viruses when it actually introduces viruses to the endpoint is an example of a Trojan program.

Virus

A virus is a program that replicates. To do so, the virus needs to attach itself to other program files and execute whenever the host program executes.

Test virus

A test virus is an inert file that is detectable by virus scanning software. Use test viruses, such as the EICAR test script, to verify that the antivirus installation scans properly.

Packer

Packers are compressed and/or encrypted Windows or Linux™ executable programs, often a Trojan horse program. Compressing executables makes packers more difficult for antivirus products to detect.

Probable virus/malware

Suspicious files that have some of the characteristics of virus/malware are categorized under this virus/malware type. For details about probable virus/malware, see the following page on the Trend Micro online Virus Encyclopedia:

Others

"Others" include viruses/malware not categorized under any of the virus/malware types.