The KRVTZ-NET IDS alerts for 2026-02-09 document network reconnaissance activities detected by intrusion detection systems, highlighting multiple suspicious IP addresses. The key technical concern is the repeated GET requests from IP 2001:470:1:332::148 targeting the /remote/logincheck endpoint on Fortigate VPN devices, associated with CVE-2023-27997, a critical vulnerability allowing unauthenticated attackers to execute arbitrary commands or gain unauthorized access. Despite the feed indicating no patch availability, Fortinet has released patches for this CVE, and organizations should verify their update status. Another notable indicator is IP 152.32.151.39 connecting approximately 15 times per hour to a submission service over TCP, suggesting brute force attempts to compromise credentials. Additional IPs (165.165.120.46, 14.176.76.54, 14.244.210.136) perform scans using the Google Webcrawler user-agent string (Mediapartners-Google), a common evasion technique to blend malicious scanning with legitimate traffic and evade detection. These activities fall under the reconnaissance phase of the cyber kill chain, representing preliminary steps attackers use to gather information before launching more damaging attacks. No confirmed exploitation or ransomware use is reported in this feed. The alerts serve as early warnings of ongoing probing that could precede targeted attacks. The use of evasion techniques complicates detection and may allow attackers to bypass traditional security controls. Overall, the threat underscores the importance of proactive defense, rapid patch management, and enhanced monitoring to prevent exploitation and maintain operational continuity.

For European organizations, the primary impact lies in the potential compromise of VPN infrastructure and submission services through brute force or exploitation of CVE-2023-27997 in Fortigate VPNs. Successful exploitation could lead to unauthorized access, data exfiltration, lateral movement within networks, and disruption of secure remote access capabilities. Given the widespread deployment of Fortigate VPNs across European enterprises and government agencies—especially in sectors requiring secure remote connectivity such as finance, healthcare, and public administration—the threat could significantly affect the confidentiality and integrity of sensitive information. The reconnaissance activity increases the risk of follow-on attacks, including credential stuffing, targeted exploitation, or ransomware deployment if initial access is gained. The use of Google Webcrawler user-agent spoofing complicates detection efforts, potentially allowing attackers to evade security controls and persist undetected. Although the current severity is low, failure to address these indicators could escalate risk and lead to operational disruptions or data breaches. The threat highlights the need for continuous vigilance and rapid response to emerging reconnaissance and exploitation attempts.

1. Immediately verify and apply all available patches for Fortigate VPN devices, specifically addressing CVE-2023-27997, to eliminate known vulnerabilities. 2. Implement strict rate limiting and account lockout policies on submission and VPN login endpoints to mitigate brute force attempts. 3. Enhance network monitoring to detect anomalous connection patterns, including repeated access attempts from single IPs and suspicious user-agent strings mimicking legitimate crawlers. 4. Deploy multi-factor authentication (MFA) on all VPN and submission services to reduce risk from credential compromise. 5. Use threat intelligence feeds to block or scrutinize traffic from IPs identified in the KRVTZ-NET alerts and other suspicious sources. 6. Conduct regular security audits and penetration tests focusing on remote access infrastructure to identify and remediate weaknesses. 7. Educate security teams on recognizing evasion techniques such as user-agent spoofing to improve incident detection and response. 8. Segment VPN and submission services from critical internal networks to limit lateral movement if compromise occurs. 9. Maintain comprehensive logging and enable alerting for repeated failed login attempts and unusual access patterns. 10. Collaborate with ISPs and national CERTs to share intelligence and respond promptly to emerging threats.