Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b4eb0cb5fc323e79…

MALICIOUS

RTF / .DOC

67.7 KB First seen: 2023-08-28
MD5: 2fa1f6aa05985845ef2cdebc49b667d5 SHA-1: 28369139145b8dcd6146e76a89bd7671f3699345 SHA-256: b4eb0cb5fc323e79086181dd8d345038e9382ecf71a35a95236982154987eb10
140 Risk Score

Malware Insights

MITRE ATT&CK
T1204.002 Malicious File: User Execution T1566.001 Phishing: Spearphishing Attachment

The sample is an RTF document that exploits the CVE-2017-11882 Equation Editor vulnerability. The document body presents a fabricated financial audit report, instructing the user to 'Enable editing' to bypass security measures. This lure, combined with the known exploit, indicates a high likelihood of the document attempting to download and execute a secondary payload.

Heuristics 4

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • \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_off00003367.bin
00f93261939381330cafc3928259e4d0f16927a4b2b3ba013452f0815d7ed6b7
rtf-objdata-decoded RTF \objdata at offset 0x3367 4161 bytes