Malicious RTF — malware analysis report

Static analysis result for SHA-256 1de9e8b54ffc4261…

MALICIOUS

RTF

46.1 KB First seen: 2023-06-13
MD5: 5d1ed3ddf8461c74a4a18966d23cb71e SHA-1: 062c9c35f1867006d08bc6898b57596439fd555f SHA-256: 1de9e8b54ffc42616a0250e991e143b603219fba18bec54dabfbfc9079d6e415
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic T1068 Exploitation for Privilege Escalation

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The \objupdate directive further suggests that the embedded object is intended to be activated automatically. The document also contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures. The primary goal appears to be the execution of arbitrary code, likely for downloading and running a secondary payload.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00005a55.bin
30d8557f616bc7ba6e7c0a02d1cbc8618cac3fc216af59e720edf80b3a6c4b23
rtf-objdata-decoded RTF \objdata at offset 0x5A55 1759 bytes