Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 38086a6e1be25a5b…

MALICIOUS

RTF / .DOC

3.8 KB
MD5: 73da18cdf16d2e02a8972ea9536e82b3 SHA-1: 5956d509c6f5434edc27fdcef14d05a0de77940b SHA-256: 38086a6e1be25a5b4dcd1aa8d5e1b9a2025d7b2b3db254551035cd25703e4e88
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an RTF document containing embedded OLE objects, specifically triggering heuristics related to the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for arbitrary code execution when the embedded object is activated. No document body or scripts were extracted, but the presence of the Equation Editor exploit is a strong indicator of malicious intent.

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_off00000085.bin
a11f8ffeb1ba21b1f1032267364f0efa64bdd4d91eec2c0382734b92ab473917
rtf-objdata-decoded RTF \objdata at offset 0x85 1665 bytes