Malicious RTF — malware analysis report

Static analysis result for SHA-256 7a1e35e303ab39df…

MALICIOUS

RTF

78.5 KB First seen: 2019-04-18
MD5: 4020a32fe67da5014bd9a22b9faaa52f SHA-1: 0dd5e2200f3d8e08b60f4e19eaaf9bc5e38cfa20 SHA-256: 7a1e35e303ab39df41f8607c42620fd4a83b94e0da12c6ca1f6aaf83ba32480b
200 Risk Score

Malware Insights

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

The RTF file contains evidence of the CVE-2017-11882 vulnerability in Microsoft Equation Editor, indicated by multiple heuristic firings including 'RTF_EQUATION_EDITOR' and 'CVE_2017_11882_ACTIVATION_RELATED'. This exploit allows for the execution of arbitrary code, which is typically used to download and run a subsequent stage malware. No document body text or scripts were extracted, limiting further analysis of the payload.

Heuristics 5

  • Split hex Equation Editor ProgID + OLE object critical CVE likely 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.
  • 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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off00009724.bin rtf-objdata-decoded RTF \objdata at offset 0x9724 1529 bytes
SHA-256: 5d9b03fd9cd6ef3ac887ddd2bf4ec9e15ec3d82af531e8247919505ffcb25120

Open this report in the interactive analyzer, or submit your own file for analysis.