Yes and no. No because an anti virus and yes because a lot of virus definitions are reported in virus killers before the virus is made. So in short no it's a Antivirus that probably make their own virus's.
Some methods they use are: Stealth mode - the virus intercepts requests from the anti-virus program and returns the information the anti-virus program would expect from a non-infected program. Self-modification or mutation - the program changes its code slightly with each infection to make it harder for anti-virus software to create a "signature" for the virus Encryption of the payload - this may obfuscate the actual virus, especially if a different encryption key is used each time. The code still has to have a decrypting function attached to allow the virus to unpack and execute. Polymorphic viruses - this is sort of a combination of the encryption and mutation tactics. The virus payload is encrypted and the decrypting function modifies itsself with each infection to make it very tough to create a signature for the virus.
A multipartite virus is a combination of a boot sector virus and a file virus. It can hide in either type of program.
A tracking cookie is not a virus. Sometimes the cookies can be from harmful sites, but the cookie itself does have a virus.
Virus program writers can have fake code within the programto prevent virus checkers from spotting the patterns of instructions which are commonly used in virus programs
how do you make fish in alexmy
rock and salimander
shrew+thorn
stop cheating
fern and earth
rock and sand
fern+earth
sand + salamandar
tree and wheel
sand + salamandar
tree and wheel
fern and earth