Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 51b76d064594b013…

MALICIOUS

RTF / .DOC

34.8 KB First seen: 2023-01-10
MD5: 0939edefc9137f4d1292c7de9d45f630 SHA-1: 10fa3de314bb4a9710f0f51262f7fef2f8cf4d76 SHA-256: 51b76d064594b013cb64babe355edc8584cab421bff316dd402c8f526ac959d0
140 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, triggered by \objupdate. This indicates an attempt to exploit a known vulnerability, likely CVE-2017-11882, to execute arbitrary code. The document body contains a lure instructing the user to 'Enable editing', a common tactic for macro-based or exploit-laden documents.

Heuristics 4

  • 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
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00005a93.bin
fe93f9042284ab8715e0f4a100236600e03b7fcaf95233322d2e791e801edbc7
rtf-objdata-decoded RTF \objdata at offset 0x5A93 1409 bytes