Memory overwrite is the replacement of data already loaded into a running process’s memory. Instead of closing or crashing the program, an attacker writes new values into variables, buffers, code regions, or configuration data so the process keeps running but behaves differently.
This matters because many security tools depend on trustworthy in-memory state. If an endpoint agent, sensor, or service is overwritten, it may still appear active while its detections, telemetry, or enforcement logic are weakened or redirected. That makes the attack harder to spot than simple process termination and can buy time for ransomware or other malware to continue operating.
In real attacks, memory overwrite can be used to tamper with security software, disable alerts, or corrupt logs before defenders notice. Defensively, teams look for unexpected memory changes, integrity failures, and mismatches between a process’s presence and its behavior. It is a reminder that “running” does not always mean “working correctly.”