A virus that contains a special routine that changes parts of the virus code with each replication to evade detection by antivirus software.
Polymorphic viruses will alter their codes to avoid being detected by anti-virus programs. These viruses encrypt themselves differently every time they infect, making it harder to track and prevent them. To prevent attacks by polymorphic viruses, specific signature codes are being developed to search for the different varieties within one type of virus.
A virus that, when replicating itself, creates copies that are different from itself, making them harder to detect. Each copy may use a different encryption algorithm, so each will look entirely different from the original and from each other. This property makes it harder for anti-virus software to recognize each strain of the virus, so the odds are higher that some strains will get through. See Also: Mutating Virus.
A polymorphic virus has a certain routine that alters a portion of the virus code each time it reproduces so that it evades detection by antivirus programs. This alteration of the code is typically done through encryption of the virus body and changes the decryption code each time it replicates.
Viruses that cannot be detected by searching for a simple, single sequence of bytes in a possibly-infected file, since they change with every replication. Similiar to a Stealth virus.
a type of malware that uses an unlimited number of encryption routines to prevent detection
a virus that can change itself to elude detection
a virus that changes its appearance in host programs
a virus that encrypts itself, changing it's 'signature' so that it is difficult to detect by anti-virus software, by using a 'mutation engine' to change the appearance of the virus in an attempt to evade detection and destruction
a virus which encrypts itself, changing its viral "signature" each time using a "mutation engine" in an attempt to evade detection and destruction
a virus which produces various copies of itself
A type of virus that changes its distinguishing characteristics as it replicates itself. Mutating in this way makes it more difficult for AV software to recognize the presence of the virus.
Self-modifying virus. By changing its code, the virus tries to make itself harder to detect.
A virus that can change itself when it replicates to avoid detection.
Virus that modifies its program code each time it attaches itself to another program or file; cannot be detected by an antivirus program. 12.6
Polymorphic viruses create varied (though fully functional) copies of themselves as a way to avoid detection from anti-virus software. Some polymorphic virus use different encryption schemes and requires different decryption routines. Thus, the same virus may look completely different on different systems or even within different files. Other polymorphic viruses vary instruction sequences and use false commands in the attempt to thwart anti-virus software. One of the most advanced polymorphic viruses uses a mutation-engine and random-number generators to change the virus code and its decryption routine. See Also: Mutating Virus
A special virus that modifies itself each time it infects a file on your computer. By modifying itself, a polymorphic virus makes it harder for anti-virus programs to find and kill all possible strains of the virus.
A virus that can change its byte pattern when it replicates, thereby avoiding detection by simple string-scanning techniques.
A type of virus that changes its code segments so that it "appears" different from one infected file to another, thereby making detection more difficult.
A virus that attempts to defeat virus-scanning software by using an algorithm to encrypt itself each time it infects a new host. The encrypted virus escapes detection by the antivirus software and then decrypts itself to infect the computer. This virus is very difficult to detect because its signature is different every time it infects a new host. More sophisticated polymorphic viruses vary their encryption methods, making them even more difficult to detect.
A Polymorphic Virus is a virus which changes itself (mutates) as it passes through host files, making disinfection a serious challenge.
A virus that changes its code to try and avoid detection.
A virus can encrypt itself with a different code each time it infects a file, which makes it harder to detect. Such a virus has to include a decryptor if it is to run as intended, but there are many ways in which the decryptor can be written. For example, NOP (No Operation) instructions and loops can be inserted into the code at random places to create potentially millions of variations.
Polymorphic virus A virus that changes its virus signature or binary pattern every time it replicates and infects a new file in order to keep from being detected by an anti-virus program.