Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 00c631724740205b…

MALICIOUS

RTF / .DOC

40.5 KB First seen: 2023-08-02
MD5: 0ca8f60433aa28b78dc0d301b7884df3 SHA-1: 681f1e8403599c6864d844bde86df3d2bda0af27 SHA-256: 00c631724740205bbd826f91c99aeffc142ab15b08b80416707989c2cf61edef
120 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that leverages the Equation Editor vulnerability. The ".objupdate" heuristic indicates that the object is designed to be activated automatically upon opening, which is a common technique for exploiting vulnerabilities like CVE-2017-11882. The document body, though heavily encoded, appears to be a lure related to marketing strategies, suggesting a social engineering pretext for the exploit.

Heuristics 3

  • 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000019cd.bin
36763d747758122205f2afcfb0188868fc8688668bd5532cd911ca775c44b18a
rtf-objdata-decoded RTF \objdata at offset 0x19CD 1676 bytes