Security research firm Digital Armaments is offering $20,000 for information on undisclosed security flaws in Microsoft's Windows OS.

Digital Armaments is offering the money as part of the 'Hacker's Challenge' until February 29. The company is also soliciting for flaws in what it calls 'Windows Diffuse Applications'.

Submitters need to illustrate a working exploit and document it, according to the company's website, which is filled with misspelled words.

There's nothing illegal about paying security researchers for flaws, but it does tend to annoy software companies whose products are affected.

Wabisabilabi, based in Switzerland, took the idea of compensating researchers a step further last year by opening a site for them to sell vulnerabilities in auctions. In response to criticism, company officials countered that researchers could sell zero-day vulnerabilities on the black market.

Microsoft, whose security vulnerabilities are generally high profile, advocates that researchers discretely alert it to software problems so users aren't put at risk. Companies generally refuse to pay for software vulnerabilities.

Digital Armaments says on its website its research team was founded in 2003, and offices were opened in the US later that year.

In addition to paying money for vulnerabilities, Digital Armaments will also apparently pay in stock or credits that can be exchanged for stock under its Digital Armaments Contribution programme.

Efforts to reach Digital Armaments on Wednesday by email were unsuccessful.