SANS Institute in IoT Botnet Warning

The SANS Institute is urging security professionals to help monitor the internet for attempts to compromise IoT devices after confirming that they’re happening virtually every minute.

The organization’s Johannes Ullrich wrote in a new note that he ran a test using an old DVR connected to a "normal" cable modem internet connection, ensuring that it wouldn’t be used to attack other systems.

“The sad part is, that I didn't have to wait long. The IP address is hit by telnet attempts pretty much every minute. Instead of having to wait for a long time to see an attack, my problem was that the DVR was often overwhelmed by the attacks, and the telnet server stopped responding. I had to reboot it every few minutes,” he explained.

“Not all attacks were successful. The attacks used various passwords, and my honeypot only allowed logins for one of them. But a couple times an hour, someone used the correct password.”

The attacks all followed a similar pattern, according to Ullrich.

They started with an attacker running commands to ensure they weren’t connected to a router or a common honeypot like cowrie.

This was followed by some additional fingerprinting, before downloading binaries of only a few hundred bytes.

Soon after, they started scanning for more vulnerable IoT devices at more than 100 connections per second.

“Interestingly, I didn't see any attempt by these bots to reset the password. The DVR was left wide open to additional attacks,” said Ullrich.

“During my experiments, the DVR was successfully attacked several times an hour.”

He urged security researchers to run the latest version of cowrie on a honeypot in order to monitor any shifts in the type of passwords being scanned for or pattern of attacks on IoT devices.

The SANS warnings come after two major IoT botnet-based DDoS attacks within the space of a few days last week.

First KrebsonSecurity was taken out by a 620Mbps blast – thought to be the biggest on record. Then French hoster OVH claimed a similar botnet had launched an attack in excess of 1Tbps.

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