Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 38c2cbf78b685c79…

MALICIOUS

RTF / .DOC

16.6 KB First seen: 2023-05-04
MD5: d6b7bad3d4cb7ba7bd432d72db7dbc92 SHA-1: d3e87bfcd82451227ad5c59690c69fa5a7ea9424 SHA-256: 38c2cbf78b685c79d9a6d37c88ce4af0737bd667aeedb6781025c1dc54a3923a
280 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The sample is an RTF document that leverages CVE-2017-11882, a critical vulnerability in the Equation Editor component. This exploit is known to be used for delivering secondary payloads, likely through embedded OLE objects. The ClamAV detection signature further confirms the exploit's nature.

Heuristics 6

  • 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.
  • Equation Editor CLSID critical RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d9b.bin
b7c12db08387c808cb4ba99ee6b140589481ef914267c4390439ed68e1c4f9a9
rtf-objdata-decoded RTF \objdata at offset 0x1D9B 4684 bytes