Hosting providers are reporting a major upsurge in attempts to hack into blogs and content management systems late last week, with WordPress installations bearing the brunt of the hackers' offensive.
WordPress installations across the world were hit by a brute force botnet attack, featuring attempts to hack into installations using a combination of popular usernames (eg, "admin" and "user") and an array of common passwords. Attacks of this type are commonplace; it is the sharp rise in volume late last week to around three times the normal volume rather than anything technically cunning or devious that has set alarm bells ringing (example here).
The primary target appears to be WordPress installations but Joomla users also reportedly took a bit of a hammering.
A list of sample WordPress usernames and passwords that have featured in the attack, put together by malware monitoring and cleanup company Sucuri, can be found here).
Early suggestions are that hackers are looking to harvest "low-hanging fruit" as quickly as possible in order to gain access to a bank of compromised sites for follow-up malfeasance, which could be anything from hosting malware to publishing phishing pages or running some sort of denial of service attack. "It's doorknob rattling, but on an industrial and international scale," notes Paul Ducklin, Sophos's head of technology for Asia Pacific.
WordPress founder Matt Mullenweg said that the attack illustrates the need to use a distinct username and a hard-to-guess password, common-sense advice that applies to using web services in general, not just for blog administration.
If you still use "admin" as a username on your blog, change it, use a strong password, if you’re on WP.com turn on two-factor authentication, and of course make sure you're up-to-date on the latest version of WordPress. Do this and you'll be ahead of 99% of sites out there and probably never have a problem. Most other advice isn't great — supposedly this botnet has over 90,000 IP addresses, so an IP limiting or login throttling plugin isn't going to be great (they could try from a different IP a second for 24 hours).
Olli-Pekka Niemi, vulnerability expert at security biz Stonesoft, outlined the range of possible motives behind the attack.
“A concern of this attack is that by compromising WordPress blogs attackers may be able to upload malicious content and embed this into the blog," Niemi said. "When readers visit the blogs in question they would be then be subject to attack, come under compromise and develop into botnets. The attacks against the word press blogs seem to be distributed, with automated attacks coming from multiple sources.”
Matt Middleton-Leal, UK & Ireland regional director of corporate security dashboard firm Cyber-Ark, said hacks on corporate blogs might be used as an access point to hack into other (more sensitive) enterprise systems. Weak passwords need to be changed pronto, he argues.
“Common usernames and weak passwords are extremely risky online, however, the dangers are compounded if users re-use the same login credentials for other sites. Once the bad guys have cracked a username and password, it’s extremely common that they’ll attempt to use the same combination for additional sites in the attempt to fraudulently use accounts, or access information such as credit card details or corporate data.
"If WordPress users have been targeted in this attack, they should immediately seek to change their username and password details for their WordPress account, but also for any other accounts for which they use the same credentials," he added. ®
Denial of service attack against US banks in January were powered from compromised WordPress sites rather than malware-infected zombie PCs. The upsurge in attempts to hack into WordPress sites last week could be a prelude to something similar.