Malicious RTF — malware analysis report

Static analysis result for SHA-256 44845f37cda70562…

MALICIOUS

RTF

45.7 KB First seen: 2023-07-19
MD5: e1fc5f838eb9814f47705d7ee79bc2c6 SHA-1: 8fabfec85ae423678121b8f2bdd5069dd0ec7eb3 SHA-256: 44845f37cda705625eec134998697dc6798adadb8f1698e2806a0e93b52e5d2c
180 Risk Score

Malware Insights

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

The RTF document contains an OLE object with a split Equation Editor ProgID, a known technique for exploiting vulnerabilities in Microsoft Office. The presence of the SE_ENABLE_LURE heuristic indicates the document attempts to trick the user into enabling editing or macros. This combination strongly suggests the document is a dropper designed to exploit an Office vulnerability and download a secondary 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00005894.bin
ad6e061796b3a4efbcb49d4f6703629398c2e8f6068e5550bfd82066a94fd87a
rtf-objdata-decoded RTF \objdata at offset 0x5894 1873 bytes