Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6f7ce7b847d8b05b…

MALICIOUS

RTF / .DOC

3.3 KB
MD5: 21dbcc30209d7c3a7c0cc108d2210859 SHA-1: aea4abd12fe1de1d9f775fda14018c2ff857d8a8 SHA-256: 6f7ce7b847d8b05bb4387ce20d998ae6d3fa2c512b6f60ac85304a2a00e1551f
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document that contains an embedded OLE object. Heuristics indicate the exploitation of CVE-2017-11882 via Microsoft Equation Editor, which allows for arbitrary code execution. The document likely serves as a malicious attachment delivered via spearphishing.

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_off00000053.bin
19b23b53b8e89b8d89e331fca265af66fe5ebad0a554483c09661c9c821baea7
rtf-objdata-decoded RTF \objdata at offset 0x53 1546 bytes