Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 20c6f18dcd705dd8…

MALICIOUS

RTF / .DOC

31.6 KB First seen: 2023-06-19
MD5: 503eaa825d4f4f28b4c51cdf6159acb3 SHA-1: 577dc7af87f60d7ff3de02922adbddd10a2800be SHA-256: 20c6f18dcd705dd885b8583561523a3731d07bdd2a8025faea96c2e136b1790d
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 specific Equation Editor ProgID, and an \objupdate directive that forces activation. This strongly suggests an attempt to exploit a known vulnerability in the Equation Editor component of Microsoft Office. The document body includes a lure to 'Enable editing', which is a common tactic to bypass macro security settings and trigger the exploit.

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_off00004e2a.bin
4ea7e72d84e4fe79ad4ff33733b3fd6e56d975917cdaab6bf6b706a026a77bd0
rtf-objdata-decoded RTF \objdata at offset 0x4E2A 1939 bytes