Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 0f95e31ffb80e6c0…

MALICIOUS

RTF / .DOC

41.8 KB First seen: 2023-02-14
MD5: fae81647ac074f66f76aa575978923d1 SHA-1: 3ecee397a696e240f09e4b64b9a0607735554935 SHA-256: 0f95e31ffb80e6c07233542a65939b920e4e76070190e4fdabe1e5dbaa03b38e
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter

The RTF document contains an embedded OLE object with an Equation Editor ProgID, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). The presence of \objupdate suggests that the OLE object is automatically activated upon opening. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security settings and facilitate exploitation.

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_off0000523c.bin
779ac950f3ab69d32d724248c34da37ab06d9094f3ca5aa4e0837933c6b28990
rtf-objdata-decoded RTF \objdata at offset 0x523C 1841 bytes