T1204.002sub-technique of T1204 User Execution
Malicious File
Linux · macOS · Windows3 pieces on this siteT1204.002 on attack.mitre.org
An adversary may rely upon a user opening a malicious file in order to gain execution. Users may be subjected to social engineering to get them to open a file that will lead to code execution. This user action will typically be observed as follow-on behavior from Spearphishing Attachment. Adversaries may use several types of files that require a user to execute them, including.doc,.pdf,.xls,.rtf,.scr,.exe,.lnk,.pif,.cpl,.reg, and.iso.
If this is happening now
Checklists and playbooks to open while the alert is still live.
Suspicious execution on an endpoint
An EDR alert, an unexplained process, or a user reporting something odd.
A remote access tool nobody installed
AnyDesk, ScreenConnect, TeamViewer, Atera, Splashtop or something like them appears on a host where IT does not use it, or a sanctioned tool connects to an account or relay you do not own.
The evidence it leaves
Where the traces live, and what each source proves and does not.
UserAssist
how MITRE says to see it
User Execution – Malicious File via download/open → spawn chain (T1204.002)
- User opens a file delivered by email, web, chat, or share. The handler application (Word/PDF reader/archiver) creates a file in user-controlled paths (Downloads, Temp, Desktop) and then spawns a new or unusual child process (e.g., powershell.exe, wscript.exe, cmd.exe, regsvr32.exe, rundll32.exe, msiexec.exe).
- User opens a downloaded document/installer leading to EndpointSecurity file create in ~/Downloads or ~/Library paths then an exec of a suspicious utility (osascript, bash/zsh, curl, chmod, open with -a Terminal). Correlates File Creation with subsequent process exec and, optionally, quarantine/LSQuarantine events.
- User or desktop application writes a new file to ~/Downloads, /tmp, or mounted removable media followed by execve of a risky interpreter/loader (bash, sh, python, perl, php, node, curl|wget piping to sh, ld.so, rdesktop, xdg-open - with unusual args).
what reduces it
- M1017 User Training. Use user training as a way to bring awareness to common phishing and spearphishing techniques and how to raise suspicion for potentially malicious events.
- M1038 Execution Prevention. Application control may be able to prevent the running of executables masquerading as other files.
- M1040 Behavior Prevention on Endpoint. On Windows 10, various Attack Surface Reduction (ASR) rules can be enabled to prevent the execution of potentially malicious executable files (such as those that have been downloaded and executed by Office applications/scripting interpreters/email clients or that do not meet specific prevalence, age, or trusted list criteria). Note: cloud-delivered protection must be enabled for certain rules.