An all-new tactic for sneaking viruses onto your computer uses an old, but ingenious, method. Security researcher Dénes Óvári revealed in the Virus Bulletin cybersecurity newsletter that a new way to inject malicious code into image files is by using grayscale.
So black-and-white JPEG images might be a good bet if you're trying to sneak code onto someone's computer. Óvári managed to pull off a proof-of-concept attack using his black-and-white method.
Óvári explained why this attack could be devastating in a blog post:
Although this is not a security breach in itself, the fact that the usage of DCTDecode for this purpose has seemingly been ruled out by the industry means that even known threats could be hidden in this way from anti-virus scanners or researchers.
So, this method would be incredibly useful for slipping by all of the defenses that we've built around our gadgets.