Malicious RTF — malware analysis report

Static analysis result for SHA-256 76539007c407ba08…

MALICIOUS

RTF

3.2 KB First seen: 2019-02-10
MD5: 5e24226d6e3a205eb0d9970123aa766c SHA-1: c1e1abfa9a6325c03ab54377399e3ad6acd0c39f SHA-256: 76539007c407ba08a1c979cb66f2d4abc71d6c29169408e4718c6aeb60f1fabb
200 Risk Score

Malware Insights

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

The RTF document contains heuristics indicating the exploitation of CVE-2017-11882 through a malformed Equation Editor OLE object. This technique is commonly used to achieve arbitrary code execution on the victim's machine. The presence of the 'EqUAtioN.3' ProgID strongly suggests this exploit vector.

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_off0000003f.bin rtf-objdata-decoded RTF \objdata at offset 0x3F 1624 bytes
SHA-256: a4b19c7aadd4e6c11321d706fd4652fea78c799c87e21ce0f47c193d1451d199

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