FritzFrog

FritzFrog is a peer-to-peer (P2P) botnet that emerged in 2020. It primarily targets Linux servers, using a custom-designed, Go-based malware to propagate across networks. Unlike many botnets relying on centralized command-and-control (C2) infrastructure, FritzFrog operates in a decentralized manner, making it more resilient to takedown efforts.

Functionality and Propagation:

The FritzFrog botnet operates by brute-forcing Secure Shell (SSH) credentials on vulnerable servers. Once a server is compromised, it becomes part of the P2P network. It then attempts to infect other servers by scanning for open SSH ports and trying common or weak passwords and previously harvested credentials. The malware uses a fileless infection technique, executing directly in memory to avoid detection by some traditional anti-malware solutions.

Architecture:

FritzFrog's P2P architecture is a key characteristic. Infected nodes communicate directly with each other, sharing tasks and updates. This removes the single point of failure presented by a central C2 server. The botnet utilizes a custom protocol for communication between peers, obfuscating its activities.

Impact:

The primary impact of FritzFrog is the unauthorized use of compromised servers for malicious activities. These activities can include cryptocurrency mining, DDoS attacks, and the distribution of other malware. The botnet's self-replicating nature can also lead to significant network congestion and resource exhaustion on infected systems.

Detection and Mitigation:

Detecting FritzFrog can be challenging due to its fileless nature and P2P communication. Security measures include:

• Strong Passwords: Enforcing strong and unique passwords for all user accounts, especially SSH access.
• Multi-Factor Authentication (MFA): Implementing MFA adds an extra layer of security to SSH logins.
• Regular Security Audits: Regularly auditing systems for vulnerabilities and misconfigurations.
• Intrusion Detection Systems (IDS): Deploying network-based IDS to detect suspicious SSH activity and P2P communication patterns.
• Software Updates: Keeping operating systems and software up to date with the latest security patches.
• Monitoring SSH Logs: Regularly monitoring SSH logs for suspicious login attempts or unusual activity.