Malicious RTF — malware analysis report

Static analysis result for SHA-256 162b3a7069481bf5…

MALICIOUS

RTF

2.8 KB
MD5: 108d096bec7b2df3e20200a64f06fcaa SHA-1: 16fbfa3938381c7d27d3aa67d03df48af8b74482 SHA-256: 162b3a7069481bf5286e5ac9fc57007dbf3c682fcd667a4faa5388fb2241fbad
180 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object specifically identified as related to CVE-2017-11882, which is a known vulnerability in Microsoft Equation Editor. The presence of \objupdate and the decoded object indicate an attempt to trigger this exploit, likely leading to arbitrary code execution. No specific family could be identified, and no further IOCs were extracted.

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 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_off00000097.bin
9a3c9f71f0455f48dbf061f486f637274843b4f63784920c9473954c9f526d1a
rtf-objdata-decoded RTF \objdata at offset 0x97 1358 bytes