Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ec0657483e9f4080…

MALICIOUS

RTF / .DOC

522.5 KB
MD5: 85f4a6c6589999ec5578d041c410f3a2 SHA-1: 0c0e891eac3ebfb9c7a9cf0db53fca0c34d387c5 SHA-256: ec0657483e9f4080bbab4c0d5ca19e9c779a9a4810e570c83df2d00417c207c2
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains an embedded OLE object with a split hex Equation Editor ProgID, indicating exploitation of CVE-2017-11882. The ".objupdate" directive forces OLE activation, which is likely intended to trigger the Equation Editor exploit. This exploit typically leads to the execution of arbitrary code, often a downloader or shellcode.

Heuristics 5

  • 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
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000066.bin
e8771f60f38f4c129d192e639176a4a5fb429d222d7d61e353fe51215e2f2d68
rtf-objdata-decoded RTF \objdata at offset 0x66 267430 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.