Dr.Web virus classification
"HLL." (High-Level Language): Viruses written in high-level programming languages (such as C, C++, Pascal, Basic, etc.). In some cases the code of the compiled HLL viruses is packed with different compression utilities (PKLITE, LZEXE, DIET, etc.).
There are several classes of HLL-viruses:
- "HLLC." (High-Level Language Companion): Viruses that employ an infection algorithm based on the manipulation of filenames in the file system. Generally the HLLC virus renames the original executable file (or moves it to another folder) and then uses the original executable filename to create a copy of the virus in its place.
- "HLLO." (High-Level Language Overwriting): Viruses that overwrite the data of the affected file.
- "HLLP." (High-Level Language Parasitic): Viruses that infect executable files without damaging the original data file.
- "HLLW." (High-Level Language Worm): Viruses that do not need any host file to spread; they just copy themselves to disk directories.
- "HLLM." (High-Level Language MassMailing Worm): Virus worm programs of mass distribution written in high-level programming languages.