Cybersecurity Researchers Uncover Creative Tactics Used by Attackers to Hide Their Tracks
A recent analysis of honeypot logs has revealed a fascinating array of tactics employed by attackers to conceal their identities and evade detection. Security expert Didier Stevens, who conducted the research, notes that these creative strategies are often humorous in their audacity, but pose significant challenges for cybersecurity professionals trying to track down malicious activity.
One common technique used by attackers is to include misleading information within User Agent Strings (UAS), which identify a device or program making a request. For instance, some UAS strings contain phrases like “authorized scan” or “scan owned,” while others use wordplay to mislead defenders into thinking the requests are benign. Stevens has observed that even entire lists of UAS strings are sometimes used, with each request selecting a new string from the list. Unfortunately, this approach often results in incomplete or malformed strings being submitted, which can still be detected.
Attackers have also been seen trying to exploit weaknesses in how UAS strings are parsed by servers. One notable example is the inclusion of a Shellshock vulnerability in UAS strings, despite the fact that Shellshock has been mitigated for over a decade. This suggests that some attackers may be scanning for vulnerabilities that still exist on outdated systems or in poorly maintained infrastructure.
Furthermore, Stevens notes that some UAS strings contain URLs or email addresses that are designed to be contacted by defenders who suspect malicious activity. These contact details often appear towards the end of the list and include a Belarusian email address that was previously linked to an attacker group. This tactic is likely intended to distract from the actual malicious activity being conducted.
The use of masscan, a popular scanning tool, has also been observed in UAS strings. Interestingly, some variants of masscan have even incorporated KGB-like names into their identifiers. These creative tactics demonstrate that attackers are continually adapting and evolving their methods to evade detection and maintain an advantage over defenders.
As cybersecurity professionals continue to grapple with the ever-changing threat landscape, Stevens’ research serves as a timely reminder of the importance of staying vigilant and proactive in monitoring UAS strings for signs of malicious activity. By being aware of these creative tactics and remaining up-to-date on the latest threats, organizations can better protect themselves against emerging attacks.
For those looking to improve their defenses, one practical takeaway from Stevens’ research is to ensure that all systems are properly configured to handle incomplete or malformed UAS strings, rather than relying solely on traditional filtering methods. By doing so, defenders can reduce the effectiveness of these tactics and stay one step ahead of attackers who seek to exploit weaknesses in their infrastructure.
Source: SANS ISC — 2026-10-04