Malicious RTF — malware analysis report

Static analysis result for SHA-256 4524caee04bbe1c6…

MALICIOUS

RTF

9.1 KB First seen: 2019-01-11
MD5: 9d41afbc812396914ecb6fbeae82e74a SHA-1: c2c76fe42badb8e5c21b9ff49829e5de5290076f SHA-256: 4524caee04bbe1c66974f5043d23efc3b8948947dd779022844b9dd23e55e233
320 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution

The RTF file contains embedded OLE object data, specifically identified as a payload for CVE-2017-11882 within Microsoft Equation Editor. This exploit is designed to execute arbitrary code upon opening the document, indicating a high likelihood of malicious intent. The ClamAV detection further confirms the presence of this known exploit.

Heuristics 7

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • 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.
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • 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_off0000003d.bin rtf-objdata-decoded RTF \objdata at offset 0x3D 4643 bytes
SHA-256: 4f22902f7ab5fe8694355273c1820189d63e4cd1236cca3e33cc2d8b8505e7da