Summary (Bottom Line Up Front)
** IP address 43.142.113.25 conducted sustained credential brute-force attacks against Telnet services over an 8-hour period on March 27, 2026, generating 394 malicious events. This represents a MEDIUM threat level with moderate sophistication targeting weak authentication mechanisms. Network defenders should immediately audit Telnet exposure and implement enhanced monitoring for credential-based attacks. **
Activity Timeline
INITIAL REPORT2026-03-31T23:54:17Z
Source: Analyst Manual Entry
IP address 43.142.113.25 conducted sustained credential brute-force attacks against Telnet services over an 8-hour period on March 27, 2026, generating 394 malicious events. This represents a MEDIUM threat level with moderate sophistication targeting weak authentication mechanisms. Network defenders should immediately audit Telnet exposure and implement enhanced monitoring for credential-based attacks.
Technical details
- Attack Vector: Sustained credential brute-force campaign targeting Telnet services (TCP/23)
- Volume: 394 attack events over 8-hour window (11:00-19:00 UTC, March 27, 2026)
- Protocols: TCP, Telnet with focus on authentication bypass attempts
- MITRE Mapping: T1110.001 (Brute Force: Password Guessing)
- Pattern Analysis: Primary attack patterns include credential capture and authentication retry mechanisms
- IOC: 43.142.113.25 (source IP, unknown geolocation/ASN)
- Targeting: Single destination port indicating focused reconnaissance and exploitation
IOCs
IP:43.142.113.25
Recommendations
- Immediately inventory and disable unnecessary Telnet services across network infrastructure
- Implement account lockout policies and rate limiting for authentication attempts on remaining legacy services
- Deploy network segmentation to isolate systems requiring Telnet access from broader network
- Enable enhanced logging and alerting for repeated authentication failures across all remote access protocols
- Consider migrating Telnet-dependent systems to SSH or other encrypted alternatives where operationally feasible