The attacker may use phishing emails with malicious attachments to deliver and execute a malicious tool, such as a reverse shell, on the victim’s machine. The tool will likely use web protocols to communicate with the attacker’s C2 server.
Tag: T1566.001
Phishing by Design – Two-Step Attacks Using Microsoft Visio Files
- Initial Access: Attackers compromise a legitimate email account and send phishing emails containing a malicious URL, either directly in the email body or within an attached .eml file. The email often impersonates a trusted entity and may include branding to appear legitimate. The URL leads to a compromised SharePoint page hosting a weaponized Visio (.vsdx) file.
- Execution: The Visio file contains a malicious URL hidden behind a clickable element, such as a “View Document” button. Victims are instructed to hold down the Ctrl key while clicking the element to access the URL, a technique designed to evade automated security scanners. This URL redirects the victim to a fake Microsoft login page designed to steal credentials.
- Persistence (Implied): Although not explicitly mentioned in the document, attackers likely leverage the stolen credentials for persistent access to the victim’s environment. This may involve establishing backdoors, creating new accounts, or modifying existing ones.
- Command and Control: After gaining access, attackers likely establish a command-and-control (C2) channel using application layer protocols like HTTP to communicate with the compromised system, issue commands, and manage the attack.
- Exfiltration: Attackers exfiltrate sensitive data from the victim’s environment over the established C2 channel.
DONOT APT’s Attack on Maritime & Defense Manufacturing
- Technique: Spearphishing Attachment (T1566.001)
- Procedure: DONOT APT used spearphishing emails with malicious attachments, likely exploiting Microsoft Office vulnerabilities (e.g., CVE-2017-11882) to deliver the initial payload. These emails were likely tailored to individuals working in Pakistan’s maritime and defense sector.
- Technique: Command and Scripting Interpreter: Windows Command Shell (T1059.003)
- Procedure: Upon successful exploitation of the vulnerability, the malicious attachment executes a Windows Command Shell command to launch the next stage of the attack.
- Technique: Scheduled Task/Job: Scheduled Task (T1053.005)
- Procedure: The malware creates a scheduled task named “Schedule” to execute the malicious DLL payload via
rundll32.exeevery 5 minutes. This ensures the malware’s persistence on the compromised system.
- Technique: Application Layer Protocol: HTTP (T1071.001)
- Procedure: The malware communicates with its command-and-control (C2) server using HTTP for receiving commands and exfiltrating data.
- Technique: Exfiltration Over C2 Channel (T1041)
- Procedure: Sensitive data stolen from the victim’s system is likely exfiltrated to the attacker’s C2 server over the established HTTP communication channel.
Tropic Trooper – Spear Phishing Attachment
Tropic Trooper crafts spearphishing emails with malicious attachments, often disguised as legitimate documents or files, to target individuals within their desired organizations. These attachments typically contain malware, such as the “Yahoyah” downloader, which enables them to establish persistence on compromised systems.
DarkComet RAT – Phishing
The attacker sent a spearphishing email containing a malicious Microsoft Word document (.doc) as an attachment. This document exploits a vulnerability (CVE-2012-0158) to execute embedded malicious code, ultimately leading to the download and execution of the DarkComet RAT payload.