Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 4a37aac541702ca2…

MALICIOUS

RTF / .DOC

313.3 KB
MD5: 3dd284d2ac652d270b5e45282af6e027 SHA-1: 8ec556c8dba61a30a05311f78c528198cbf5782f SHA-256: 4a37aac541702ca28b08b8179ec5dab6b2c674f92ecbf1400aaf6a3727f2daa5
122 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that decodes to a PE file, indicating an exploit targeting the Equation Editor. The ".objupdate" heuristic suggests that the OLE object is designed to be activated automatically. The decoded object is a suspicious artifact that likely serves as the initial stage of a multi-stage attack, potentially downloading and executing further malicious content.

Heuristics 4

  • Decoded Equation Editor payload + PE critical RTF_EQUATION_EDITOR
    RTF decodes to an Equation Editor ProgID adjacent to OLE activation and the same decoded object stream contains embedded PE bytes. This matches the Equation Editor exploit surface used by CVE-2017-11882 / CVE-2018-0802 documents, while requiring payload evidence to avoid flagging benign Equation references.
  • \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
  • 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_off00001997.bin
5c95f8cea83cfbefe97ebcac0f2fc656a6b27b25161fac53b1598de36f87bf4c
rtf-objdata-decoded RTF \objdata at offset 0x1997 156801 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.