Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 650c3cef83cf637c…

MALICIOUS

RTF / .DOC

48.6 KB First seen: 2022-05-27
MD5: 15ec8fda6c191434841c07b919e45ada SHA-1: f1a773a6cc8d4a8817b756c85dc75c79ff9bc879 SHA-256: 650c3cef83cf637c6ae2288dc789b41033c348f53ccfa48d78568e3957404989
180 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The sample is an RTF document that contains embedded OLE object data, specifically triggering critical heuristics for CVE-2017-11882 via the Equation Editor. This exploit allows for arbitrary code execution, which is typically used to download and execute a secondary payload. The presence of the ".objupdate" directive further indicates an attempt to force OLE activation and trigger the exploit.

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.
  • 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
  • \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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d4d.bin
148a9bca3abc748d7d87d6f8377b154149c443c3f2bd251dc8188634a3bdd18f
rtf-objdata-decoded RTF \objdata at offset 0x1D4D 4175 bytes