Researchers have found that hackers lingered in compromised networks for an average of about two weeks, a period that remains a critical window for investigators. A detailed analysis by Sophos, a company specializing in cyber threat defense, explains how long intruders stay inside before they are detected or before their operational goals are completed and they exit on their own terms.
The duration is measured from the moment an attacker breaches a system until disclosure or until all necessary actions are completed and the intruder disengages. The study highlights that when quick action is needed, attackers may miss something, allowing defenders to close gaps faster but also underscoring the risk of longer undetected dwell times.
According to the report, the longest dwell times are observed in small businesses, where intruders tend to remain for about 21 days, and in educational institutions, where the figure rises to roughly 34 days. These extended timelines give cybercriminals more chances to observe user behavior, harvest sensitive data, and plan subsequent incursions across similar networks.
Industry observers note that increasing dwell times correlate with greater threat potential. More days in a system enable attackers to map internal processes, escalate privileges, and refine their methods for avoiding detection. This trend has coincided with a shift toward more cautious, methodical intrusion patterns, rather than rapid, opportunistic breaches alone.
Historically, cyber criminals have relied on mass email campaigns to distribute malicious software, often disguising payloads as ordinary documents. This tactic remains a persistent entry point and is frequently used to initiate initial footholds in networks before broader exploitation unfolds.