Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 9fa8125990ca0482…

MALICIOUS

RTF / .DOC

19.8 KB
MD5: f42efe8fa86f136318cc21d72c5225be SHA-1: 6b181b2fa34aa5133de34e9eb73406ebb6a62254 SHA-256: 9fa8125990ca04826c2cc5a22160779a1c809c87426ae535e228638c7a6fd603
180 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that exploits CVE-2017-11882. The Equation Editor object is specifically targeted, indicating a known exploit technique. The presence of `RTF_EQUATION_EDITOR` and `CVE_2017_11882_ACTIVATION_RELATED` heuristics strongly suggests this vulnerability is being leveraged. The ` tf1 0 s24

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_off00001ad0.bin
0a53a063f22e6c8dbe95ce366cea8717bbaca7108ac07df63b648a408e16b54d
rtf-objdata-decoded RTF \objdata at offset 0x1AD0 1717 bytes