Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 673af81ba4d91c2a…

MALICIOUS

RTF / .DOC

3.3 KB First seen: 2022-12-10
MD5: 67a2cd30fcf4184b1515ba628b1e5710 SHA-1: c9fb5d6a4d412336df170c355aad3721f40c284f SHA-256: 673af81ba4d91c2aaa5a445a7399b8985a7144b58945e776470b32e059cbbcc4
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF document contains an embedded OLE object that leverages a known vulnerability in Microsoft Equation Editor (CVE-2017-11882). The object's ProgID and activation method strongly indicate exploitation of this vulnerability to achieve arbitrary code execution. No document body text or scripts were extracted, but the exploit itself is sufficient to classify the attack pattern.

Heuristics 5

  • Obfuscated Equation Editor ProgID + activation critical CVE related RTF_EQUATION_EDITOR
    RTF decodes to an Equation.3 ProgID from top-level \objdata hex after nested RTF junk groups are ignored, and the document also contains \objemb plus \objupdate activation. This is an obfuscated Equation Editor exploit surface associated with CVE-2017-11882 / CVE-2018-0802 families, but no exact malformed MTEF CVE primitive was recovered from this object.
  • 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.
  • \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
  • 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_off00000077.bin
ea43b25c9410a53406cc3c70c0d3d4abf3e5ad82311a0d4e1b4a5545f4a5784b		 rtf-objdata-decoded RTF \objdata at offset 0x77 1560 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.