If you have a WordPress site, you better check to make sure you've got a strong password on it. And also maybe install some plugins (linked to in the article below) to increase security/limit login attempts.
Security analysts have detected an ongoing attack that uses a huge number of computers from across the Internet to commandeer servers that run the WordPress blogging application.
The unknown people behind the highly distributed attack are using more than 90,000 IP addresses to brute-force crack administrative credentials of vulnerable WordPress systems, researchers from at least three Web hosting services reported. At least one company warned that the attackers may be in the process of building a "botnet" of infected computers that's vastly stronger and more destructive than those available today. That's because the servers have bandwidth connections that are typically tens, hundreds, or even thousands of times faster than botnets made of infected machines in homes and small businesses.
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According to CloudFlare's Prince, the distributed attacks are attempting to brute force the administrative portals of WordPress servers, employing the username "admin" and 1,000 or so common passwords. He said the attacks are coming from tens of thousands of unique IP addresses, an assessment that squares with the finding of more than 90,000 IP addresses hitting WordPress machines hosted by HostGator.