The Symantec patent specifically refers to a "virus detection system (that) operates under the control of P-code to detect the presence of a virus in a file having multiple entry points," but the reach of the patent could be much more broad, said Michael Schallop, director of intellectual property at Symantec.More details at InfoWorld
"What's patented is a technology to use an intermediate language to drive anti-virus functionality such as scanning and emulation," he said.
Symantec obtains anti-virus patent

Symantec obtained a patent that allows researchers to program AV software to scan multiple areas of a file for signs of infection. This technology is used in Symantec's anti-virus product line since 1999.