Miscreants have fired up a large army of remote-controlled computers to get around GitHub's login rate-limiting policies, designed to thwart attempts to brute-force guess the passwords for its users' accounts.
The bots, most likely unwitting PCs compromised by malware, have attacked the online source-code repository from "nearly 40,000 unique IP addresses", each trying to crack programmers' passwords, the company said this week.
"These addresses were used to slowly brute force weak passwords or passwords used on multiple sites. We are working on additional rate-limiting measures to address this," the website's team wrote.
While GitHub tries to develop new tech, it has rolled out a blocklist of commonly used weak passwords that people can no longer use on the service.
It has also reacted proactively "out of an abundance of caution," and has reset some user accounts' login credentials "even if a strong password was being used. Activity on these accounts showed logins from IP addresses involved in this incident."
As usual, the company recommended users consider enable two-factor authentication to their accounts to provide another line of defense against nefarious hacker probes.
GitHub is a popular target of hackers thanks to the vast piles of source code and suchlike material stored on it, some of which are held in private repositories. It has been a repeated victim of distributed denial-of-service attacks, and fell offline in early October after being hit by a huge multi-day attack.
It strikes us that GitHub's recent bout of probing may stem from crackers using the 38 million user details that were sucked out of Adobe recently to check for duplicate logins on other sites. Never use the same password and username combination on other sites, no matter how fringe. ®