Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ff7138279b44672b…

MALICIOUS

RTF / .DOC

23.7 KB First seen: 2023-01-27
MD5: c4e9a5e14abab4b306a69b6f0dcc9322 SHA-1: 5c2f3bb439e7097c0f76c350a5e082227b3fccae SHA-256: ff7138279b44672bcf9b82d6a3d67f899b2214242b885c13745691fc53c8d6a0
220 Risk Score

Malware Insights

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

The sample is an RTF document that leverages the CVE-2017-11882 vulnerability in Microsoft Equation Editor. Heuristics indicate the presence of an OLE object and automatic linking, along with specific indicators for Equation Editor exploitation and activation. The document body contains a lure instructing the user to 'Enable editing', a common tactic to bypass security measures and facilitate the exploitation of the embedded malicious object.

Heuristics 6

  • 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.
  • 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
  • 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_off000041d6.bin
c100daf5910d133f01bd9ddd67752b255a4e04f77dfede461bdeb82a91a5bb2e		 rtf-objdata-decoded RTF \objdata at offset 0x41D6 1615 bytes

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