Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b3dce0eddcd75c8e…

MALICIOUS

RTF / .DOC

19.0 KB First seen: 2022-07-07
MD5: bccd94208e57dccd96dc7654852b81b0 SHA-1: fefc30ba752d5b5ace50ddea6261c9f5ed58c324 SHA-256: b3dce0eddcd75c8e613c0836d462f070136f6c06802f19f49f615960f48e9434
200 Risk Score

Malware Insights

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

The sample is an RTF document containing an OLE object with an embedded Equation Editor payload. The critical heuristic CVE_2017_11882_EQUATION_OLE10NATIVE indicates a likely exploit for CVE-2017-11882, which allows for arbitrary code execution. The presence of ".objdata" and ".objupdate" sections further supports the exploitation of OLE object vulnerabilities.

Heuristics 5

  • Equation Editor Ole10Native payload — CVE-2017-11882 likely critical CVE likely CVE_2017_11882_EQUATION_OLE10NATIVE
    RTF decodes to an activated Microsoft Equation 3.0 OLE storage whose payload is a high-entropy Ole10Native stream rather than normal Equation Native/MTEF data. This is a weaponized Equation Editor RCE delivery shape consistent with CVE-2017-11882/CVE-2018-0802.
  • Ole10Native stream in RTF OLE object high CVE related RTF_OLE10NATIVE_STREAM
    RTF contains an embedded OLE object with an Ole10Native stream. This is a strong payload-container signal and is related to Word/OLE exploit delivery, but it is not specific enough on its own to assign a CVE.
  • 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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000005b7.bin
bbf217b0eb7c47e6674cf2f32251f9a389a7668b0f03ee0ee111eb9e4c4a6bdd
rtf-objdata-decoded RTF \objdata at offset 0x5B7 4285 bytes