The decentralized botnet attack botnet, FritzFrog is resurged after a big decline by the beginning of this year. According to Akamai, the number of attacks by FritzFrog nodes has reached more than 12x, compared to the mid-January records of the security company. The infection rate of the botnet has also shown a growth of 10 times, which is an alarmingly big number.
Sophisticated peer-to-peer architecture and code
FritzFrog is a peer-to-peer botnet campaign, currently targeting mostly healthcare, education, and government servers. Several countries are affected by the botnet attacks while China is in the first spot. It can target any device that exposes an SSH server such as cloud instances, servers, routers, and more. After infection, it can run any payload on the device.
The first version of the FritzFrog is a sophisticated botnet that is decentralized and had some interesting properties to make it unique. Akamai summarizes FritzFrog as:
- Constantly updating – Databases of targets and breached machines are exchanged seamlessly
- Aggressive – Brute force is based on an extensive dictionary; by comparison, DDG, another recently discovered P2P botnet, used only the username “root”
- Efficient – Targets are evenly distributed among nodes
- Proprietary – The P2P protocol is completely proprietary, relying on no known P2P protocols such as μTP
FritzFrog is being updated very frequently; sometimes more than once a day. Its binary is written in Golang and can be compiled to run different architectures. It generally runs under the name of ifconfig, nginx, apache2, or php-fpm and it is packed with UPX.
WordPress attacks are on the way
The new version of FritzFrog has a WordPress server tracking infrastructure. However, its target list is currently empty; the threat actors might fill those spaces any time. It currently has no module for cracking or identifying WordPress targets, which indicates it is under preparation for a WordPress attack wave.
Akamai has released a FritzFrog detection tool that checks the running processes for possible FritzFrog executable names and it listens to 1234 port, which the botnet uses to connect. It also checks the TCP traffic of 5555 port for a possible connection to the Monero pool. The security company also recommends the following actions for protection from FritzFrog botnet attacks:
- Always Keep systems updated and patched
- Implement passwordless login using strong key management and rotation system
- Enable system login auditing with alerting
- Monitor the authorized_hosts file on Linux
- Configure explicit allow list of SSH login
- Disable root SSH access
- Enable Akamai cloud-based DNS protection with threats and unrelated business applications such as coin mining set to block