SysmonObject Access

Event 2: File Create Time Changed

A process changed a file creation time. This event helps track the real creation time of a file. Attackers may change file time attributes to hide their tracks.

Technical Details

Sysmon Source

Event ID: 2

Sysmon- Object Access

Event Description

A process changed a file creation time. This event helps track the real creation time of a file. Attackers may change file time attributes to hide their tracks.

Key Log Fields

  • UtcTime - UTC timestamp when file creation time was changed
  • ProcessGuid - Process GUID that modified the file time
  • ProcessId - Process ID
  • Image - Process executable path
  • TargetFilename - Full path of the file whose timestamp was modified
  • CreationUtcTime - New creation time set on the file
  • PreviousCreationUtcTime - Original creation time before modification

MITRE ATT&CK® Mapping (1)

T1070.006defense-evasion
Timestomp

Adversaries may modify file time attributes to hide new files or changes to existing files. Timestomping is a technique that modifies the timestamps of a file (the modify, access, create, and change times), often to mimic files that are in the same folder and blend malicious files with legitimate files. Both the `$STANDARD_INFORMATION` (`$SI`) and `$FILE_NAME` (`$FN`) attributes record times in a Master File Table (MFT) file.(Citation: Inversecos Timestomping 2022) `$SI` (dates/time stamps) is displayed to the end user, including in the File System view, while `$FN` is dealt with by the kernel.(Citation: Magnet Forensics) Modifying the `$SI` attribute is the most common method of timestomping because it can be modified at the user level using API calls. `$FN` timestomping, however, typically requires interacting with the system kernel or moving or renaming a file.(Citation: Inversecos Timestomping 2022) Adversaries modify timestamps on files so that they do not appear conspicuous to forensic investigators or file analysis tools. In order to evade detections that rely on identifying discrepancies between the `$SI` and `$FN` attributes, adversaries may also engage in “double timestomping” by modifying times on both attributes simultaneously.(Citation: Double Timestomping) Timestomping may be used along with file name [Masquerading](https://attack.mitre.org/techniques/T1036) to hide malware and tools.(Citation: WindowsIR Anti-Forensic Techniques)

Contents