Understanding the Surge in Brute Force Attacks

Brute Force Targeted Attacks

As companies of all sizes continue to operate in an era of distributed teams and cloud services, hackers are intensifying their efforts to breach critical infrastructures. One alarming trend we have seen  increase is brute force attacks, an organized attempt to guess valid credentials until a match is found. This rise in brute-force attempts has serious implications for businesses that rely heavily on Virtual Private Networks (VPNs), remote desktop portals, and SSH services.

Brute Force Attacks Introduction

Over the past few months and even last week, we have observed an elevated surge in brute-force assaults aimed at VPN solutions, web application authentication portals, and SSH services. These attacks frequently exploit weak or commonly used usernames and passwords, leveraging proxy services and anonymizing networks such as TOR. In many cases, attackers use generic or easily guessed user credentials to gain unauthorized access to businesses. These types of passwords should never be used, but especially on externally facing applications. Even for companies with effective IT security controls and a well-established cybersecurity program, keeping pace with evolving threats can be daunting, as cybercriminals continually adapt their methods to evade detection.

Background: Why the Surge in Brute Force Attacks?

Recent cybersecurity reports highlight an overall upswing in brute-force activity. Some of this escalation began recently, when security researchers started to notice spikes in login attempts on firewalls, VPN devices, and other gateway services. A critical factor contributing to this trend is the easy availability of anonymizing tools. Bad actors can cycle through various proxy or VPN services, effectively rotating exposed IP addresses to evade conventional blocking lists. This cat-and-mouse game has made it significantly more challenging to rely solely on traditional threat intelligence feeds, which identify known malicious sources.

What is a Brute Force Attack?

Brute-force attacks rely on trial-and-error methods to crack login credentials, cycling through millions of usernames and passwords until a correct combination is found. While this method may seem rudimentary, the use of automated scripts means that, given enough time and access to unprotected services, attackers can eventually succeed. These attacks can cause surges in network traffic, potentially leading to denial-of-service conditions, and, if successful, open a gateway for deeper intrusion into the network.

Critical Services Under Siege

Many notable services are on the front lines of the brute-force campaign. In VPN environments, solutions from Cisco, Checkpoint, Fortinet, and SonicWall have been notably targeted, along with remote desktop (RD) web interfaces. Meanwhile, wireless network devices have also seen an uptick in attack attempts. Stepping beyond VPNs and remote access gateways, web authentication portals, and public-facing SSH services have increasingly drawn the attention of threat actors.

Common Brute Force Attack Vectors

Whenever credentials are easy to guess, whether through default device logins or recycled passwords, cybercriminals seize the opportunity. Attackers gather login data from stolen breach databases, social engineering tactics, and company directories. Once they have a treasure trove of usernames, they hammer away at a target’s login interface with automated scripts. If a company lacks strong authentication controls and checks, or imposes minimal controls on failed login attempts, brute force attacks can continue unimpeded, dramatically increasing the chances of compromise.

Potential Risks and Business Impacts

When attackers successfully gain unauthorized access, the repercussions can be severe and far-reaching. Beyond data theft, malicious activity inside the network can lead to sabotage, financial fraud, or the introduction of advanced persistent threats that remain dormant for future exploitation. Furthermore, repeated login attempts can trigger an avalanche of account lockouts, grinding legitimate activities to a halt. In the worst cases, the volume of brute force traffic alone may cripple computer resources, resulting in denial-of-service events. For many companies, even a short-lived incident equates to costly disruptions and tarnished reputations.

Indicators of Compromise (IOCs)

Early recognition of attack patterns is essential for staying ahead of attackers. Suspicious peaks in failed VPN logins or unusual SSH activity often provide the first red flag. IT administrators can keep track of malicious IP ranges and known problem credentials, updating firewall or intrusion prevention rules accordingly. Since attackers rely on widespread infiltration, each newly discovered IOC becomes part of a mosaic that offers deeper insight into threat behavior. Differentiating genuine user errors from automated attacks is the key to effective monitoring, particularly in high-traffic environments.

Strengthening Authentication

Implementing multi-factor authentication (MFA) is one of the most effective and easiest-to-implement strategies. Even if a username and password are compromised during a brute force attack, the additional step required for authentication makes unauthorized access considerably harder. Requiring longer, more complex passwords, alongside rotating credentials on a regular schedule, further complicates the success of any brute force attack. Another recommended approach is to configure lockout policies that throttle repeated login attempts, deterring automated tools from endlessly guessing.

Network and Infrastructure Hardening

Companies should regularly apply firmware and software updates to their VPN appliances, firewalls, and other network infrastructure components. Patching known vulnerabilities promptly helps reduce the window of opportunity for intruders. Intrusion detection and prevention systems (IDPS) bring real-time visibility into unusual request patterns. At the same time, properly segmented network architectures limit the extent to which an intruder can move laterally after an initial breach. Consistently checking configurations, especially default settings, winds up being just as important as flashy new security tools.

Continual Monitoring & Testing

Proactive vigilance can make a strong defense even stronger. Automated scans, IT risk assessments, and routine penetration tests or vulnerability assessments keep team members aware of potential entry points, offering a roadmap for remediation before attackers discover the same vulnerabilities. Many businesses also maintain blocklists of known threat infrastructure. By combining thorough audit log reviews with robust anomaly detection, security professionals can spot an uptick in failed password attempts or any strain of anomalous network activity before it evolves into a full-blown incident.

“A single compromised login can open the door to a cascade of cybersecurity threats,” says John Pohlman, Senior Security Consultant at Tanner Security.

Tanner’s Role in Protecting Your Network From Brute Force Attacks

At Tanner, we understand that long-term security is not just about reacting to incidents; it is about creating a strong IT security program that evolves over time. Brute force attacks can catch even seasoned IT departments off guard. By partnering with Tanner, companies receive ongoing cybersecurity consulting to harden their IT security program and help reduce IT risk. Helping our customers stay one step ahead of cybercriminals.

Security Assessments and Architecture Reviews

To shield networks from emerging brute force tactics, Tanner provides comprehensive assessments that examine the maturity of infrastructure. We review everything from the design of remote access policies to the strength of authentication protocols. Whether it is a new application launch or a legacy networking environment, our recommendations address both the technical and procedural facets crucial for an end-to-end solution.

Ongoing Support and Training

Through training services, Tanner elevates security awareness at every level of your business. From stress-testing login workflows to simulating brute force attempts in controlled drills, this holistic approach empowers teams with the knowledge and tools they need to maintain a resilient posture. As part of our partnership-centric model, we remain engaged with clients long after initial consultations, providing continuous support, threat intelligence, and strategy updates.

Brute Force Attack Conclusion

The modern cyber threat landscape demands a lot of work and robust, layered defense strategies. As brute force attackers refine their scripts and discover new techniques, companies must respond proportionately. Strengthening authentication credentials, regularly monitoring potentially malicious traffic, and tailoring response plans for rapid containment are all essential ingredients of robust cybersecurity. Ultimately, proactive measures reduce the likelihood of catastrophic breaches and position organizations to stay resilient.