Query: intelligence brief on T1204.002
Matching passage: T1204.002 Malicious File. Tactics: execution. Description: 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](https://attack.mitre.org/techniques/T1566/001). 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.(Citation: Mandiant Trojanized Windows 10) Adversaries may employ various forms of [Masquerading](https://attack.mitre.org/techniques/T1036) and [Obfuscated Files or Information](https://attack.mitre.org/techniques/T1027) to increase the likelihood that a user will open and successfully execute a malicious file. These methods may include using a familiar naming convention and/or password protecting the file and supplying instructions to a user on how to open it.(Citation: Password Protected Word Docs) While [Malicious File](https://attack.mitre.org/techniques/T1204/002) frequently occurs shortly after Initial Access it may occur at other phases of an intrusion, such as when an adversary places a file in a shared directory or on a user's desktop hoping that a user will click on it. This activity may also be seen shortly after [Internal Spearphishing](https://attack.mitre.org/techniques/T1534).
Near-miss passage: T1204.004 Malicious Copy and Paste. Tactics: execution. Description: An adversary may rely upon a user copying and pasting code in order to gain execution. Users may be subjected to social engineering to get them to copy and paste code directly into a [Command and Scripting Interpreter](https://attack.mitre.org/techniques/T1059). One such strategy is "ClickFix," in which adversaries present users with seemingly helpful solutions—such as prompts to fix errors or complete CAPTCHAs—that instead instruct the user to copy and paste malicious code. Malicious websites, such as those used in [Drive-by Compromise](https://attack.mitre.org/techniques/T1189), may present fake error messages or CAPTCHA prompts that instruct users to open a terminal or the Windows Run Dialog box and execute an arbitrary command. These commands may be obfuscated using encoding or other techniques to conceal malicious intent. Once executed, the adversary will typically be able to establish a foothold on the victim's machine.(Citation: CloudSEK Lumma Stealer 2024)(Citation: Sekoia ClickFake 2025)(Citation: Reliaquest CAPTCHA 2024)(Citation: AhnLab LummaC2 2025) Adversaries may also leverage phishing emails for this purpose. When a user attempts to open an attachment, they may be presented with a fake error and offered a malicious command to paste as a solution, consistent with the "ClickFix" strategy.(Citation: Proofpoint ClickFix 2024)(Citation: AhnLab Malicioys Copy Paste 2024) Tricking a user into executing a command themselves may help to bypass email filtering, browser sandboxing, or other mitigations designed to protect users against malicious downloaded files.