Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 2c15ecc6295d759b…

MALICIOUS

RTF / .DOC

31.4 KB First seen: 2023-03-24
MD5: 726a0733d2ec70bcb70137e792b63080 SHA-1: 86a9ad3151dcf1373525c27326e6707c9d0b2cdc SHA-256: 2c15ecc6295d759b0320660ad376c358f52bdeb014e5829145fade95f6ea8a8d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing an OLE object with a split Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The \objupdate directive forces OLE activation, and the document includes a lure to enable editing, common for macro-based malware droppers. The exploit is likely intended to download and execute 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_off00005505.bin
8ea58dac03b62e372c6f88a69724c8ef9c98ad65569c47968fc8fdb381762973
rtf-objdata-decoded RTF \objdata at offset 0x5505 1595 bytes