Ah well, it looks like the spam holiday is over!
Two weeks ago, the web hosting firm McColo was shut down and the amount of worldwide spam dropped by two-thirds. You may well have noticed this in your email inbox, I certainly did. From hundred a day to just a few in one fell swoop.
McColo was a command and control centre for a number of botnets (networks of infected computers sending out spam and other malicious items) and since its closure, these botnets have had no centralised command and the owners have been looking for new hosts.
The bots have been trying to ‘phone home’ but getting no reply. However, they remain infected and once a new host is found, they can be reactivated and it all gets back to ‘normal’.
One particular botnet, the Srizbi botnet, controls around 450,000 infected computers and apparently accounted for about a half of all spam on this planet of ours. Moreover, the Srizbi bots (the individually infected computers) are thought to be programmed with a mathematical formula that, in the event of a shutdown, generates a random but unique web address to check for updates. This in turn means that as soon as Srizbi’s owners find a new web hosting firm, all they need to do is set up a site with that unique address and the botnet will be fully functional again.
Amazing the amount of time, money and resources spent on bombarding us with often patently obvious frauds. Even more amazing is the fact that, despite only getting a reply to roughly 1 in every 12.5 million emails sent, they still make a fortune!
However, it looks like at least some of the spammers have already found alternatives as the amount of spam is on the rise once more, back up to somewhere between one half and two-thirds of its former glory. Noticable in ye olde inbox.