Password hints easily snaffled from Windows PCs

Punters' password hints are easily extracted from the latest Microsoft Windows machines, security researchers have discovered.

TrustWave SpiderLabs uncovered a key called "UserPasswordHint" during wider research into how the Redmond operating system stores password hashes. Subsequent studies showed it was easy to extract and decode password hints from the registry on both Windows 7 and Windows 8 machines. The value stored is obscured with the addition of zeros but not encrypted.

So an eight-line script was all it took to determine the clear-text version of password hints. The researchers have integrated user password hint decoding into Metasploit, the widely used computer security tool that has applications in both penetration testing and hacking.

Obtaining password hints would narrow things down for a hacker running a brute-force or social engineering attack. However other security researchers have noted that password hints aren't supposed to be secret.

A hint can easily extracted from Mac OS X machines too, according to Mac and smartphone security expert Graham Lee. Password hints are, by their very nature, a security trade-off. "You increase the risk of telling others about your password in return for reducing the risk that you'll forget it yourself," Lee explained. ®