One of the observations I read in the aftermath of the Krebsonsecurity DDOS was that the vulnerable IOT devices often permit telnet (port 23 and non-encrypted)

One of the observations I read in the aftermath of the Krebsonsecurity DDOS was that the vulnerable IOT devices often permit telnet (port 23 and non-encrypted) connections. A common approach to take over one of these devices starts with brute-forcing the login prompt. Once compromised and running malware, the device proceeds to probe random IP addresses for open telnet ports to spread further. The uptick in port 23 connection attempts has coincided with the perceived spread of IOT malware.