Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c086a5bf6d7f4586…

MALICIOUS

RTF / .DOC

27.8 KB First seen: 2023-04-20
MD5: 1cf063099adda44ae796e1abbdc0c4b6 SHA-1: 8d5091defe3bf7431e357079da14640a237716ec SHA-256: c086a5bf6d7f4586a1c1f03d6228efafe36e769910c60e01aa9b4fb63ba3f588
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, a known exploit technique. The document also includes a lure instructing the user to 'Enable editing', indicating an attempt to bypass security measures and trigger the embedded exploit. The presence of ".objupdate" further suggests an attempt to force OLE activation.

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_off0000451f.bin
8edeb8af30407a8960737cd722a148af52f504618427f070ca877671ad53623b
rtf-objdata-decoded RTF \objdata at offset 0x451F 1666 bytes