Your Linux-based home router culd succumb to a new Telnet worm, Remaiten

The worm takes advantage of exposed Telnet services with weak passwords to infect routers and other embedded devices

Building botnets made up of routers, modems, wireless access points and other networking devices doesn't require sophisticated exploits. Remaiten, a new worm that infects embedded systems, spreads by taking advantage of weak Telnet passwords.

Remaiten is the latest incarnation of distributed denial-of-service Linux bots designed for embedded architectures. Its authors actually call it KTN-Remastered, where KTN most likely stands for a known Linux bot called Kaiten.

When scanning for new victims, Remaiten tries to connect to random IP addresses on port 23 (Telnet) and if the connection is successful, it attempts to authenticate using username and password combinations from a list of commonly used credentials, researchers from ESET said in a blog post.

If the authentication succeeds, the bot executes several commands to determine the system's architecture. It then transfers a small downloader program compiled for that architecture that proceeds to download the full bot from a command-and-control server.

The malware has versions for mips, mipsel, armeabi and armebeabi. Once installed it connects to an IRC (Internet Relay Chat) channel and waits for commands from attackers.

The bot supports a variety of commands for launching different types of denial-of-service attacks. It can also scan for competing DDoS bots on the same system and uninstall them.

It's surprising that many networking devices still use Telnet for remote management, instead of the more secure SSH protocol. It's also unfortunate that many devices ship with Telnet service open by default.

Device owners should use one of the many free online port scanning tools to check if their router has port 23 open and should try to shut down the Telnet service from the device's Web-based administration interface. Unfortunately many gateway devices provided by ISPs to their customers don't give users full access to the management features.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Cool Tech

Crucial Ballistix Elite 32GB Kit (4 x 8GB) DDR4-3000 UDIMM

Learn more >

Gadgets & Things

Lexar® Professional 1000x microSDHC™/microSDXC™ UHS-II cards

Learn more >

Family Friendly

Lexar® JumpDrive® S57 USB 3.0 flash drive 

Learn more >

Stocking Stuffer

Plox Star Wars Death Star Levitating Bluetooth Speaker

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

GGG Evaluation Team

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Steph Mundell

LIFEBOOK UH574

The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi

STYLISTIC Q702

The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott

STYLISTIC Q702

My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?