Hackers actively stealing Wi-Fi keys from vulnerable routers

Still using the password from the back of the router? Oops!

Hackers have graduated from planting malware on the vulnerable routers supplied to consumers by various ISPs towards stealing Wi-Fi keys.

Andrew Tierney, a security researcher at UK consultancy Pen Test Partners, noticed the switch-up in tactics in attacks against its honeypot network over the weekend.

Customers of UK ISP TalkTalk are among those at the most immediate risk of having their Wi-Fi credentials stolen. The TalkTalk router firmware fix fails to solve this problem because it reverts customers back to a default password hackers might already have snatched, Pen Test Partners warns.

TalkTalk published a fix to the TR-064 / Annie issue. What this does is disable the TR-064 interface and reset the router. It resets the passwords, back to the ones written on the back of the router.

[But] nearly all customers never change their Wi-Fi key from that written on the router. So, the Annie worm and hackers have already stolen their Wi-Fi keys, and the TalkTalk fix simply resets the router, to the exact same keys that have already been stolen!

The TR-064 vulnerability means that hackers can access or alter the device's LAN configuration from the WAN-side using TR-064 protocol. “Attackers appear to have cottoned on to the fact that the TR-064 vulnerability can be used for more than just recruiting the router into a botnet,” Pen Test Partners explain.

“We run a TR-064 / Annie honeypot and saw requests last night, which alerted us to the issue. Here you can see someone trying to steal our Wi-Fi network key using the ‘GetSecurityKeys’ command.”

The hacker has to be physically close to the router to compromise the Wi-Fi, a major mitigating factor. However, if you know the SSID (also stolen using the Annie worm) they can use databases such as https://wigle.net to find your victim’s house.

TalkTalk and other ISP customers that use similar routers are likely to have had their Wi-Fi keys stolen, opening them up to hackers, Pen Test Partners concludes. The security consultancy recommends that TalkTalk take the radical step of replacing customer routers in all cases where it’s impossible to rule out compromise.

Users in the short term can act themselves by resetting their router (follow the TalkTalk advice) and then changing their Wi-Fi password. TalkTalk supplies its customers with routers manufactured by D-Link, as previously reported. Other ISPs using kit from other manufacturers may be affected since the TR-064 / Annie issue is not restricted to D-Link. Pen Test Partners’ honey pot shows hacker activity targeting UK in particular, which means that TalkTalk’s customers may be at greater risk than most.

El Reg ran this response past TalkTalk, which said that the situation was under control and that kit replacement was needed and offered the following statement.

As is widely known, the Mirai worm is an industry issue, affecting many ISPs around the world. A small number of TalkTalk customers have been affected, but we can reassure customers that no personal information is at risk. If customers have an issue connecting to the internet, they should visit our help site where they can find a guide that will show them how to reset their router. There is no need for customers to reset their wifi password.

“I think TalkTalk haven’t realised that the Wi-Fi keys and related TR-064 issues are different consequences of the same bug last week,” Pen Test Partners Ken Munro told El Reg. “Whilst they’re fixing the bug and also blocking TCP port 7547 [maintenance interface] which it uses, it’s too late in the case of stolen Wi-Fi keys, as most users have never changed them from the default values.”

“The fix resets the Wi-Fi key to the same value that has already been exposed,” he concluded.

Lee Munson, security researcher at Comparitech.com, added: “If TalkTalk routers have, as one expert claims, been compromised following the theft of Wi-Fi passwords, customers of the telecoms company could potentially be in for a whole lot more pain following the well-publicised massive data breach and recent connectivity issues experienced by the firm." ®

Bugnote

¹Mirai and the TR-064 issue are different, but there are many similarities. The Mirai malware uses default credential, TR-064 exploits a vulnerability. The TR-064 bug started to be referred to as "Annie" though it’s also referred to as TR-06FAIL.