Malicious RTF — malware analysis report

Static analysis result for SHA-256 08e2e96ce3011731…

MALICIOUS

RTF

8.1 KB First seen: 2019-05-16
MD5: fe5b9797a9defcb481f16f97f9a8c82d SHA-1: d64b356c09688a2576adc01ad602ffcf2e8168be SHA-256: 08e2e96ce3011731935a581a7aa6795477bd68a221e5db92eee431e0f6855a35
240 Risk Score

Malware Insights

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

The RTF file contains embedded OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (CVE-2017-11882). This vulnerability allows for the execution of arbitrary code on the victim's machine when the document is opened. The presence of ".objupdate" further indicates an attempt to force OLE activation. The file is classified as malicious due to this exploit.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • 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.
  • ClamAV: Doc.Exploit.CVE_2017_11882-6934206-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Exploit.CVE_2017_11882-6934206-0
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000003b.bin rtf-objdata-decoded RTF \objdata at offset 0x3B 4139 bytes
SHA-256: 9c1e2d166d40d6de41f628860065d5775782c1fdd7b7401fdb24d9626c34b516