Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 59ec21c2cbea8337…

MALICIOUS

RTF / .DOC

221.1 KB
MD5: 42686e015262b24113364a15b0ee4983 SHA-1: f15fc92c8fcdd53b212993b0f1bf12e68570e114 SHA-256: 59ec21c2cbea8337c61be946ea039cce2316085c64f83aff71e2fa2c72517104
120 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document that contains embedded OLE object data. Critical heuristic firings indicate the presence of the CVE-2017-11882 Equation Editor vulnerability, which is exploited via the objupdate directive. This vulnerability allows for arbitrary code execution when the document is opened.

Heuristics 3

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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000004ef.bin
0f56a4df62ba34c616b1c81bdba6bdf64d482375491e5ae1926b0b89c2b6394d
rtf-objdata-decoded RTF \objdata at offset 0x4EF 4163 bytes