Malware Analysis Report - VIBE Bot
Executive Summary
The analyzed ELF binary (SHA256: e28abfb7868c987e42c3d460434961db17841166342fa7c24db35f37af341586) is a sophisticated botnet client designed for distributed denial-of-service (DDoS) attacks. The malware connects to a command-and-control (C&C) server to receive attack instructions and can execute multiple types of network floods.
Verdict: MALICIOUS
Key Findings
1. C&C Infrastructure
- Primary C&C Domain:
yn.eoow.cn (encrypted with XOR 0x2E)
- Authentication Token: "Engine" (encrypted)
- C&C Port: 51975 (0xCAF7)
- DNS Servers Used: 8.8.8.8 and 53.0.0.2
- Fallback IP: 191.826.803 (initial hardcoded value)
2. Attack Capabilities
The malware supports 11 different DDoS attack methods:
- TCP SYN Flood - Overwhelms targets with TCP SYN packets
- UDP Flood - Generic UDP packet flooding
- NUDP (New UDP) - Enhanced UDP flooding variant
- VSE Attack - Valve Source Engine query flood
- GRE IP Flood - Generic Routing Encapsulation flood
- TCP ACK Flood - Two variants for ACK packet flooding
- TCP SACK2 - Selective Acknowledgment exploit
- STD HEX UDP - Standard hexadecimal UDP flood
- Socket Flood - Raw socket flooding
- WRA Flood - Wrapper flood attack
3. Evasion Techniques
- Process Name Disguise: Renames itself to "httpd" to appear legitimate
- Anti-Debugging: Uses ptrace to prevent debugger attachment
- Signal Handling: Ignores/handles termination signals (SIGTERM, SIGINT, etc.)
- Binary Self-Deletion: Attempts to delete itself from disk after execution
- Encrypted Configuration: C&C details are XOR encrypted (key: 0x2E)
- Memory Obfuscation: Re-encrypts sensitive data after use
4. Persistence & Defense
- Killer Module: Terminates competing malware and security tools
- Process Monitoring: Scans
/proc/*/exe and /proc/*/maps for targets
- Fork Bomb Protection: Uses prctl to ensure child processes die with parent
- Network Resilience: Implements retry logic with exponential backoff
5. Communication Protocol
- Uses custom binary protocol over TCP
- Message format: [2-byte length][payload]
- Implements keepalive mechanism (every 6 cycles)
- Non-blocking sockets with select() for multiplexing
Technical Details
Entry Point Analysis
The malware's main function (VIBE_main_botnet_client) performs the following initialization:
- Sets up anti-termination signal handlers
- Implements anti-debugging protection
- Deletes the original binary from disk
- Forks to background and detaches from terminal
- Initializes attack method table
- Spawns killer process
- Enters main C&C communication loop
Attack Implementation
Each attack method is implemented as a separate function that:
- Parses attack parameters (target IP, port, duration, packet size)
- Creates raw sockets
- Generates malformed packets with spoofed source addresses
- Sends packets in a tight loop to maximize bandwidth usage
C&C Communication Flow
- Decrypt C&C domain from configuration
- Resolve domain using public DNS servers
- Connect to C&C server
- Authenticate with "Engine" token
- Receive attack commands
- Execute specified attack method
- Maintain connection with periodic keepalives
Indicators of Compromise (IoCs)
Network
- C&C Domain:
yn.eoow.cn
- C&C Port: 51975
- DNS queries to 8.8.8.8 and 53.0.0.2
- Large volumes of malformed TCP/UDP traffic
- Process name "httpd" making unusual network connections
Host
- Binary hash: e28abfb7868c987e42c3d460434961db17841166342fa7c24db35f37af341586
- Process masquerading as "httpd"
- Attempts to read
/proc/*/exe and /proc/*/maps
- Self-deletion behavior
- Anti-debugging via ptrace
Behavioral
- Immediate fork and background execution
- Terminal detachment (setsid)
- Closing of stdin/stdout/stderr
- High CPU/network usage during attacks
- Killing of security tools and competing malware
Conclusion
This is a professional-grade DDoS botnet client with sophisticated evasion capabilities and multiple attack vectors. The malware is designed to be part of a larger botnet infrastructure, likely used for DDoS-for-hire services or coordinated attacks. The presence of anti-analysis techniques, encrypted configuration, and process hiding mechanisms indicate a well-developed threat actor.
Recommendations
- Block the C&C domain
yn.eoow.cn at network perimeter
- Monitor for processes named "httpd" making unusual network connections
- Implement rate limiting and DDoS protection measures
- Deploy endpoint detection focusing on:
- Process name spoofing
- Anti-debugging behavior
- Unusual
/proc filesystem access
- Self-deletion patterns
- Use the provided hash for file-based detection
- Monitor DNS queries to 8.8.8.8 from unusual processes
Analysis completed on: [Current Date]
Total analysis time: Approximately 35 minutes