Malicious RTF — malware analysis report

Static analysis result for SHA-256 bfc6cb663772226a…

MALICIOUS

RTF

62.6 KB First seen: 2023-08-28
MD5: 0d96d7b0ce9460f00cb5d86a4adc492a SHA-1: e2f7a8ba38450edd0fe857e9d0ca16389891f58d SHA-256: bfc6cb663772226a7c71a8e8337a40986ddb6d03e75b91087c82d72417fd3886
160 Risk Score

Malware Insights

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

The file is an RTF document containing an embedded OLE object that exploits the CVE-2017-11882 vulnerability in Microsoft Equation Editor. The document also contains a lure instructing the user to 'Enable editing', indicating a social engineering attempt to bypass security measures. The exploitation of CVE-2017-11882 is a critical finding, strongly suggesting the file's purpose is to execute malicious code.

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_off000027b1.bin
842de9ef4c58958ad27ee457b44d41d17b528ed5a51599098983d2d27d1de2c4
rtf-objdata-decoded RTF \objdata at offset 0x27B1 4176 bytes