Related Clues:
- Swamp gas
- Noxious atmosphere
- Marsh emanation
- Unhealthful atmosphere
- Noxious influence
- High-tech invader
- Common cold cause
- Unhealthy atmosphere
- Pervasive ickiness
- It may be written in code
- Bug first discovered in 1898
- Unwholesome or foreboding atmosphere
- Foul vapours or unwholesome air
- An unwholesome atmosphere
- Hidden destructive code in computer program