Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 890c8869fead37e0…

MALICIOUS

RTF / .DOC

4.6 KB
MD5: 369951e0b3c0b82743f1a9db8f94d77d SHA-1: bd045a1079155d7c647e06bbef1a32d222d15739 SHA-256: 890c8869fead37e018ed204229d6ac86dbe2f6cd54fe8a7458a1d30754520c6e
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 embedded OLE object data, specifically triggering heuristics related to Equation Editor and CVE-2017-11882. The ".objupdate" directive forces OLE activation, indicating an attempt to exploit this vulnerability. This likely leads to arbitrary code execution, although no specific payload or second-stage download was identified in the provided evidence.

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_off000000c3.bin
234bbf12a691e3541c220afac6b9c69ad6aee640369de0dc2ed54d48e52c8e44
rtf-objdata-decoded RTF \objdata at offset 0xC3 2112 bytes