Recent Target data heist of 40 million credit card records has many worrying about impact of memory-only malware. After the initial exploitation, these programs simply load themselves into RAM — they don’t install themselves on the hard drive. Antimalware scanners would love to stick to memory if they could; the performance hit would evaporate. Scanning memory can be literally thousands of times faster than scanning a hard drive — it’s even much, much faster to scanning an SSD. The only challenge to antimalware software is keeping up with the sheer number of new programs that appear every day.”]
Source: https://www.csoonline.com/article/2608848/should-you-worry-about-memory-only-malware-.html