Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 2dd41b55bdfd562b…

MALICIOUS

RTF / .DOC

25.0 KB First seen: 2022-03-15
MD5: f672d4d734aef0eac45fbcf951094a14 SHA-1: 8fe450113b0a5072e891b5772b97a7459833267c SHA-256: 2dd41b55bdfd562b47288845f6ea8b0d1b962f93389b5ba0c80096f48c2d0707
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains an embedded OLE object specifically related to Equation Editor, triggering heuristics for CVE-2017-11882. This indicates the document is designed to exploit this known vulnerability upon opening. The exploit likely leads to arbitrary code execution, allowing for further malicious actions.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • 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 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000076.bin
ddd895b966f1fdebc625287a4933cf4b33f382217d45c0f2514c6d514abb1c7f
rtf-objdata-decoded RTF \objdata at offset 0x76 8786 bytes