Malicious RTF — malware analysis report

Static analysis result for SHA-256 beee8f4e5a1f3f96…

MALICIOUS

RTF

36.7 KB First seen: 2023-07-12
MD5: d7479f88b48b68d72fd81997c45eab97 SHA-1: 778d7e45b511e8d2c1ea5c670c62ef261df0a99f SHA-256: beee8f4e5a1f3f96bba7e4e125bbdfafacfaa5628b51325f6635473ce003fd65
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059.005 Visual Basic

The RTF document contains an embedded OLE object, specifically targeting the Equation Editor, and uses an \objupdate directive to force activation. The document body includes a lure instructing the user to 'Enable editing' to view the content, which is a common technique for malware droppers. The embedded OLE object is highly suspicious and likely exploits a known vulnerability to execute a malicious payload.

Heuristics 5

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off00004c47.bin
9d3d4cd11a6c21afed25f522c84686f69da7a0f99a1de6a71a5d26050a618148
rtf-objdata-decoded RTF \objdata at offset 0x4C47 1462 bytes