Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0c09e1c758693f15…

MALICIOUS

RTF / .DOC

30.8 KB First seen: 2023-05-03
MD5: 3f087a35d751f5ad8bf64f351dac9745 SHA-1: 1c342e84d4fafc3c0e7b622d4296bc317d0009e7 SHA-256: 0c09e1c758693f15e6a79cc6c8d4dec5c7b69eeadf9c9c9c37d29edca9f4b895
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The RTF document contains an embedded OLE object with an Equation Editor ProgID, a known vector for exploiting vulnerabilities like CVE-2017-11882. The \objupdate directive indicates an attempt to automatically activate this object upon opening. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to bypass security measures and trigger the exploit. The primary IOC is the file's SHA256 hash.

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_off00005a76.bin
8d0491c51cd671456cb32cdea73f2a66d98a27a803cdb7886e920879d7ce60ac
rtf-objdata-decoded RTF \objdata at offset 0x5A76 1396 bytes