Examples associated with ransomware attack monitoring are described herein. One example includes a monitor module to monitor files stored on the system for sequences of file accesses that match a predefined pattern of file accesses. An investigation module is activated based on a sequence of file accesses that match the predefined pattern. The investigation module logs actions taken by processes to modify files. A reaction module pauses a set of processes operating on the system based on the logging performed by the investigation module, and resumes legitimate processes.