Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 66e21bc194bee5da…

MALICIOUS

RTF / .DOC

72.6 KB
MD5: 03513b4c8d65cf8f4b4c5297e1fb5a94 SHA-1: 882ae7114eec03e32ce91f8ba106bed448ceb17b SHA-256: 66e21bc194bee5da464ea18a13ac6b7427ca11df560f34157f2b61feb9790add
180 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that leverages the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This exploit is designed to execute arbitrary code, likely to download and run a second-stage payload. The high entropy of the decoded object data further suggests it contains executable content.

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.
  • \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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000057b.bin
e1d5acc4d6ff08effa87dc01a9435e8a59262ffe5a2aeafb186b84d1e5af18ce
rtf-objdata-decoded RTF \objdata at offset 0x57B 4182 bytes