Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 54ce91828ec84f4b…

MALICIOUS

RTF / .DOC

50.4 KB First seen: 2023-02-22
MD5: a3761aad1b480f55b9cd3e8019527da8 SHA-1: 9bb5cf649468487f4757c03b2b8e06049770567a SHA-256: 54ce91828ec84f4b785711e8b24b0dbae9dc713e43ed7ca60e8831ba8516b793
160 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 that exploits the CVE-2017-11882 vulnerability in the Microsoft Equation Editor. The document body contains a lure instructing the user to enable editing and content, a common tactic for macro-based malware. The exploitation of CVE-2017-11882 allows for arbitrary code execution, which is typically used to download and execute a second-stage payload.

Heuristics 5

  • 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
  • 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_off00001cb8.bin
db1cb487eac4512f29033205610d7cf17db2c4ac2d4473e7e27ad2ce7e028f2a
rtf-objdata-decoded RTF \objdata at offset 0x1CB8 3135 bytes