Finnish anti-virus vendor F-Secure identified Farid Essebar, 18, who was arrested by Moroccan authorities, as the author of some Mytobs.
"We know that [Essebar] had also authored several of the Mytob variants since February this year," F-Secure's Mikko Hypponen wrote on the company's blog. "However, he's not behind all of them."
Early analysis by others, including Ken Dunham, senior engineer with VeriSign iDefense, pegged Zotob and Mytob as close relations. "Hackers took the Mytob worm code and replaced the e-mail function in Mytob with the exploit of the MS05-039 vulnerability," said Dunham two weeks ago when the Zotob attack first began.
While there have been too many variants of Mytob for one individual to create -- Symantec's count is above 200 -- Hypponen made note of other clues that tie Essebar, who went by the hacker nickname of 'Diabl0,' to Mytob.
"We know Diablo aka Farid Essebar, was associated with '0x90-Team.' For example, some earlier Mytob variants downloaded additional components"said Hypponen.
The 0x90-Team had been operating as an underground gathering place for bot authors, Hypponen added. As of Monday, however, the site was inaccessible.
That Essebar/Diabl0 wasn't the only Mytob hacker was evident Monday as several security firms, including Symantec, identified a brand-new Mytob variant. Dubbed "Mytob.jh," the worm opens a backdoor to the infected PC, blocks access to numerous security sites, and tries to disable more than 560 different security programs.
The arrest of Essebar and his cohort, Atilla Ekici, won't put a stop to either Mytob or similar bots, such as the pervasive IRCbot.
"Several people have access to Mytob source code and have been making their own variants," said Hypponen. "And there are the competing groups, such as "m00p," who seem to be behind several of the IRCbot variants that were using PnP [Plug and Play] vulnerability to spread."