From Bruce Schneier’s “Gathering ‘Storm’ Superworm Poses Grave Threat to PC Nets” (Wired: 4 October 2007):
Storm represents the future of malware. Let’s look at its behavior:
1. Storm is patient. A worm that attacks all the time is much easier to detect; a worm that attacks and then shuts off for a while hides much more easily.
2. Storm is designed like an ant colony, with separation of duties. Only a small fraction of infected hosts spread the worm. A much smaller fraction are C2: command-and-control servers. The rest stand by to receive orders. …
3. Storm doesn’t cause any damage, or noticeable performance impact, to the hosts. Like a parasite, it needs its host to be intact and healthy for its own survival. …
4. Rather than having all hosts communicate to a central server or set of servers, Storm uses a peer-to-peer network for C2. This makes the Storm botnet much harder to disable. …
This technique has other advantages, too. Companies that monitor net activity can detect traffic anomalies with a centralized C2 point, but distributed C2 doesn’t show up as a spike. Communications are much harder to detect. …
5. Not only are the C2 servers distributed, but they also hide behind a constantly changing DNS technique called “fast flux.” …
6. Storm’s payload — the code it uses to spread — morphs every 30 minutes or so, making typical AV (antivirus) and IDS techniques less effective.
7. Storm’s delivery mechanism also changes regularly. Storm started out as PDF spam, then its programmers started using e-cards and YouTube invites — anything to entice users to click on a phony link. …
8. The Storm e-mail also changes all the time, leveraging social engineering techniques. …
9. Last month, Storm began attacking anti-spam sites focused on identifying it — spamhaus.org, 419eater and so on — and the personal website of Joe Stewart, who published an analysis of Storm. I am reminded of a basic theory of war: Take out your enemy’s reconnaissance. Or a basic theory of urban gangs and some governments: Make sure others know not to mess with you.