ViruXine.W32 virus hides their presence by changing the underlying executable code. This Virus code mutates while keeping the original algorithm intact, the code changes itself each time it runs, but

Polymorphic viruses use a built-in mutation engine to re-encrypt or otherwise alter their binary representation with each infection, producing a different byte signature every time to evade static signature-based detection. The core algorithm and malicious payload remain functionally identical across all variants; only the code's appearance changes.

A metamorphic virus fully rewrites its entire code - not merely re-encrypts it - on each replication, which is a more advanced transformation than the mutation-with-intact-algorithm behavior described in the question.

Dravidic virus is not a recognized classification in any standard malware taxonomy and is a fabricated distractor.

A stealth virus conceals its presence by intercepting OS calls and returning falsified file or memory data, which is a hiding technique unrelated to code mutation.