Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 822b550d4a5a64cb…

MALICIOUS

RTF / .DOC

2.17 MB
MD5: dc92a9e38f2d53c87c4cb49696876887 SHA-1: 0463da8686d7d855aef029ce8eea8a2177fdf088 SHA-256: 822b550d4a5a64cbe34058a8af2b249fc134f437fd09f86435d3324fa813571f
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains multiple indicators of malicious activity, including embedded OLE objects and specifically the Equation Editor object. The critical RTF_EQUATION_EDITOR heuristic firing, along with the CVE_2017_11882_ACTIVATION_RELATED heuristic, strongly suggests exploitation of CVE-2017-11882. The extasciitilde{}objupdate directive further indicates that the embedded OLE object is intended to be activated, leading to arbitrary code execution.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000011e1.bin
9cf623e4216caaa9fa1a8547bad1a4f0feb2f0340496498eb86d9ae96d77d59a		 rtf-objdata-decoded RTF \objdata at offset 0x11E1 28917 bytes
objdata_01_off00019b49.bin
e7360513b374e8393bd4c4b28adef7bcaf4b4715376d4f2c5515615499218833		 rtf-objdata-decoded RTF \objdata at offset 0x19B49 550268 bytes

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