Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5e14bc6d617734a0…

MALICIOUS

RTF / .DOC

1.14 MB First seen: 2023-01-30
MD5: 97fa945e53d039902a831f852dc05b2c SHA-1: beaf02c58439d18218dbd25d938ed50ba613654a SHA-256: 5e14bc6d617734a033325d914b5e9997ad23f4d29fdb0c2e9bd2c9991991fe79
222 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with decoded Equation Editor payload, strongly indicating exploitation of CVE-2017-11882. The presence of excessive hex-encoded data and a high-entropy extracted artifact further suggests the object is a packed or obfuscated malicious executable. The file's structure and heuristics point to a classic exploit delivery mechanism.

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.
  • 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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~1199KB of hex-encoded data inside \objdata sections — may hide a payload
  • 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_off0000007e.bin
04e216724d8d228c95b6cb3422d8f09ae37ee936740339d3aa75c4e45b890773
rtf-objdata-decoded RTF \objdata at offset 0x7E 600014 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact entropy is 8.00, consistent with packed or encrypted content.