Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 70cc59b2655c5aba…

MALICIOUS

RTF / .DOC

70.9 KB First seen: 2023-09-04
MD5: 3e31389dee8a3e8f3f6310b7c3047bb4 SHA-1: 863c3dea08fb08ca21ab536ee000593a72f7a0de SHA-256: 70cc59b2655c5abafacf09d8f9894d029abe73735a651760a8225693ab881639
220 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1204.002 Malicious Link: Malicious File T1059 Command and Scripting Interpreter T1059.005 Command and Scripting Interpreter: Visual Basic

The sample is an RTF document exploiting CVE-2017-11882 via the Equation Editor. The document body contains text designed to trick the user into enabling editing, which is a common lure for macro-based malware. The embedded OLE object and objdata sections are indicative of exploit code execution.

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
  • \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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • 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_off000041a8.bin
1049768e6c548d26704ac90a1e83b1c629d2ee8d81b512e2cc81d287ae47fa78
rtf-objdata-decoded RTF \objdata at offset 0x41A8 4167 bytes