The beef over news of a worm targeting Macs, and the identity of the researcher who claimed to have created the malware, took an even stranger turn Wednesday as death threats were allegedly posted to his or her blog, which was then reportedly hacked.

In return, the researcher leveled charges at a security expert known for taking on Apple.

The hubbub started earlier this week, when a researcher responsible for the Information Security Sell Out (InfoSec) blog announced a proof-of-concept worm that exploited a Mac OS X vulnerability which Apple missed in a May round of patches. The vulnerability exploited by the worm was in mDNSResponder, a component of Apple's Bonjour automatic network configuring service, InfoSec said then.

Criticism from Mac users and other security researchers was almost immediate, with the former focusing on crude insults and the latter concentrating on InfoSec's refusal to identify himself or herself, or prove that the worm existed.

The latter group questioned InfoSec's motives and the veracity of his or her claims. "Let's see this worm deliver a destructive payload in the wild and then we can talk again," said a user identified as Ted Wood. "Until then, you're just hot air."

"If you are a legitimate researcher, you have an obligation to publish your findings so they can be tested," said Stephen, another user on the same comment list. "Any good researcher would do this."

According to InfoSec, some of the comments left earlier included death threats. In a posting -- since deleted, more on that below -- from Tuesday, InfoSec listed comments he refused to allow to be posted to the blog. Among them:

- "You are lucky you are anonymous or I would put a bullet in your head for this!" -- Anonymous

- "Nice try with the FUD [fear, uncertainty and doubt]. You are full of **** there is no such thing as an Apple Worm." -- Jeff

- "I dare you to demonstrate this at Defcon you ***** Microsoftie. We will drag you out, put a bullet in you, and bury your body so deep it will take a nuclear blast to find your body." -- Anonymous

Tuesday night, the InfoSec blog's title changed to "Security Information..." and all former postings, which began in January, had been deleted. When asked via e-mail Wednesday to explain the changes, InfoSec answered: "Blog was hijacked somehow. Also the blog stating I am associated with PHC on another Blog is false and a myth created by Dave Maynor who is involved in the hijacking of the Blog."

InfoSec was likely referring to a posting on a blog dubbed "Security Ripcord" at a site run by a Texas-based security consultancy called Cutaway. In a long entry posted this morning, Don Weber, a.k.a. Cutaway, said an informant had told him that that InfoSec is actually "LMH," a researcher best known for having co-authored January's Month of Apple Bugs (MoAB) campaign. The source also claimed, said Weber, that LMH was part of a group that calls itself "Phrack High Council," or PHC, a self-described group of "black hat" hackers.

No way, said InfoSec.

"The claim that we are LMH or MoAB or PHC are all wrong," InfoSec wrote in a second e-mail Wednesday. "These came from Maynor assuming that we are all one and the same because we have all attacked his creditability."

Dave Maynor, a researcher who last year was involved in a very public spat with Apple over a wireless hack demonstration he and a colleague gave at the Black Hat security conference, refused to be drawn into the argument with InfoSec. "I am not even going to comment on that stupidity," Maynor wrote in an e-mail responding to an offer to rebut or comment on InfoSec's allegations.

Prior to this, Maynor was most recently in the news as one of several researchers who found vulnerabilities in the Windows beta of Apple's Safari 3.0 within hours of the browser's release.

Kevin Finisterre, who partnered with LMH for MoAB, said he doubted that InfoSec and LMH were one and the same. "From what I am aware of it's not the same guy," Finisterre said in an e-mail.

"I can certainly say that the underground is always abuzz about mDNS bugs," Finisterre added. "If you have ever looked at the source code you would see it is clearly a large target surface. mDNS is a nasty beast."

Apple has been largely forgotten in the heated back-and-forth between InfoSec on one side, Mac users and other researchers on the other. The only response the Cupertino, Calif. computer maker has offered up on the issue, and alleged unpatched vulnerability, was made by a spokesman Tuesday. "Apple takes security very seriously and has a great track record of addressing potential vulnerabilities before they can affect users," said Anuj Nayar Tuesday.