Ashley Madison users warned of password risk

Loathe as I am to write the words “Ashley Madison” again, there’s one development which definitely needs to be shared with anyone who created an account on the ill-fated site.

As Ars Technica reports, the hacked adultery website appears to have coughed up a piece of data that was previously felt secure: users’ passwords.

When the Ashley Madison hackers leaked close to 100 gigabytes worth of sensitive documents belonging to the online dating service for people cheating on their romantic partners, there seemed to be one saving grace. User passwords were cryptographically protected using bcrypt, an algorithm so slow and computationally demanding it would literally take centuries to crack all 36 million of them.

Now, a crew of hobbyist crackers has uncovered programming errors that make more than 15 million of the Ashley Madison account passcodes orders of magnitude faster to crack.

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You can read full details in the Ars Technica article, which credits the “CynoSure Prime” cracking team with identifying a critical weakness in the code that the Ashley Madison website was using to create password hashes for its database. It’s an interesting read for coders and fans of cryptography.

But the important message for people who had created accounts on the Ashley Madison website is not *how* their password can be extracted from the site’s leaked database, but what that means now.

And what it means is that if CynoSure Prime has worked out how to extract millions of passwords in a relatively short period of time, so could criminal hacking gangs. Therefore, if you have used the same password anywhere else on the internet, you need to change it immediately.

It’s always important to have strong, hard-to-crack, and – crucially – unique passwords for every account you create. You should never re-use passwords, just like you shouldn’t ever re-use loo paper.

Because if you do re-use passwords, hackers can take advantage of the fact. If they have your email address and Ashley Madison account password, what’s to stop them trying to use that password to unlock your web mail account, or other online services?

And, it’s worth remembering, that some of the accounts that tumbled out of the Ashley Madison hack were created long long ago, perhaps years before you started your current relationship. Way back then, maybe you were much more careless with your password choices, and didn’t think twice about using easy-to-guess passwords or using the same password in different places.

Avoid future headaches, have a long hard think about your passwords – and make sure all of them are unique. If, like me and 99.999% of the population, you can’t remember lots of complicated passwords invest in a decent password manager.

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• Here's what an Ashley Madison blackmail letter looks like
• Now it's Ashley Madison wives who are receiving blackmail letters
• 'Bring me the head of the AC/DC-loving Ashley Madison hacker'
• Suicide and Ashley Madison
• Ashley Madison: Betting site offers odds on who will be exposed
• 'Yes. I was a member of the Ashley Madison website. But I wasn’t there to cheat on anyone'
• Ashley Madison hack could expose 37 million 'cheating dirtbags'
• No Ashley Madison, you weren't burgled by terrorists
• Ashley Madison users warned of password risk
• Cracked Ashley Madison passwords consistent with years of poor security
• Post-hack, Ashley Madison offers members full and free account deletion
• Don't judge Ashley Madison users too quickly, their accounts may be fake
• Just who is joining the Ashley Madison website?
• Fembots land Ashley Madison in hot water with the FTC
• Ashley Madison's marketing department clearly didn't get the memo
• Ashley Madison: Further thoughts on its aftermath
• Ashley Madison hack claims another victim: Its CEO
• Ashley Madison slammed with $1.6 million fine for devastating data breach

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Graham Cluley •   @gcluley

Graham Cluley is a veteran of the cybersecurity industry, having worked for a number of security companies since the early 1990s when he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows. Now an independent analyst, he regularly makes media appearances and is an international public speaker on the topic of cybersecurity, hackers, and online privacy. Follow him on Twitter, Mastodon, Bluesky, or drop him an email.