Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d3490497dc5b10ae…

MALICIOUS

RTF / .DOC

1.02 MB
MD5: 63872255e1e06276058f5a469a872ee0 SHA-1: 2144ffbd849240ca023c626c03c49ec49eca8770 SHA-256: d3490497dc5b10ae961480b105a14ad808507b85423a62b07b0f9018e351164f
222 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The RTF document contains an OLE object specifically related to the Equation Editor vulnerability, CVE-2017-11882. The presence of large, high-entropy hex data within the OLE object suggests it is used to hide a malicious payload. The objupdate directive further indicates that the OLE object is intended to be activated, likely leading to the execution of the embedded exploit.

Heuristics 6

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1067KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \objdata section(s) — embedded OLE objects
  • 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_off000000c6.bin
08c61a89e8edc8b6ec05d4bda77a7e6f7a688152dbcd4b49465c8578b1450fc5
rtf-objdata-decoded RTF \objdata at offset 0xC6 533668 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.