A large-scale brute force attack campaign, first identified in January 2025, is actively targeting edge security devices like VPNs, firewalls, and gateways from multiple vendors, including Palo Alto Networks, Ivanti, and SonicWall. The attack utilizes a vast network of 2.8 million unique IP addresses, with the majority originating from Brazil, followed by countries like Turkey, Russia, and Argentina. The campaign has intensified in recent weeks, focusing on compromising login credentials for critical infrastructure exposed to the internet. This type of attack, which involves repeatedly attempting to guess usernames and passwords, significantly increases the risk of unauthorized access to sensitive networks and data.
The campaign, confirmed by the Shadowserver Foundation, employs residential proxy networks and compromised devices, including routers from brands like MikroTik, Huawei, and Cisco, to carry out the brute force attacks. The distributed nature of the attacking IPs suggests the involvement of a large botnet orchestrating the efforts. Devices targeted in the attack are vital for remote access and security, such as VPN gateways, firewalls, and IoT appliances. Once compromised, these devices can be used for further malicious activities, including the theft of sensitive data or integration into larger botnets for additional attacks.
Shadowserver CEO Piotr Kijewski emphasized that these attacks go beyond simple scans—they involve direct login attempts, significantly increasing the likelihood of credential theft. The threat actors appear to be attempting to breach login credentials across a range of exposed devices. This campaign follows a series of similar brute force attacks, including those in April 2024, which targeted VPNs from vendors like Check Point and Fortinet. These earlier attacks, many of which were routed through TOR exit nodes and proxy services, show a growing trend of cybercriminals leveraging increasingly sophisticated techniques to breach remote access infrastructure.
In response to these escalating threats, cybersecurity agencies from the Five Eyes nations, such as CISA and NCSC, have issued urgent guidance for manufacturers to improve the security of edge devices. Their recommendations include eliminating default passwords, ensuring real-time threat detection capabilities in device firmware, and strengthening logging protocols. The recent vulnerabilities in Ivanti and SonicWall devices further underline the need for swift patch management to prevent exploitation. With brute force attacks becoming more refined and widespread, organizations must take immediate action to secure their edge devices, implement multi-factor authentication, and regularly update their defenses to protect against these persistent threats.
