New software has been published on the Internet that could be used to exploit a known flaw in Internet Explorer.
The code, which was posted Monday to the Milw0rm.com web site, exploits a recently patched flaw in Microsoft's browser. It could be used to run unauthorised software on a computer that was not updated with the latest Microsoft patches, security experts warn.
The vulnerability was first discovered by security researcher HD Moore who posted code last July that could be used to crash the browser.
Microsoft patched the flaw in February, but some security researchers say that it will get more attention from criminals because of this latest exploit code.
"This type of vulnerability has been very popular with malicious attacks in the past and we expect to see its usage increase substantially, now that exploit code is publicly available," security vendor Websense warned in a note published on 26 March.
Researchers at eEye Digital Security say the Milw0rm code works on IE6, but not on the latest version of Microsoft's browser.
"We've tested it against IE 7 and haven't got it to work yet," said Andre Protas, director of eEye's Preview research service.
Protas said that more dangerous exploit code is likely to be released in the future.