Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 eaadcf1991c30f13…

MALICIOUS

RTF / .DOC

23.7 KB First seen: 2022-08-02
MD5: e61c03bde0af05fe5b3709c1cf995e8c SHA-1: f868c17c7199e116e4437c9cbd670df61ad06797 SHA-256: eaadcf1991c30f1354cb1d73a37dc3f2a16528ee30df14fd5de02027ab4e2e32
180 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object that leverages the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This vulnerability is known to be used for arbitrary code execution, indicating the document is designed to exploit this flaw to deliver a secondary payload. The presence of OLE object data and specific Ole10Native stream details strongly suggests this exploit vector.

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 2 \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_off000019bc.bin
d35e72aec39346cf75f55213b946abb38510aacc75f5604ca814e6c398c2230e
rtf-objdata-decoded RTF \objdata at offset 0x19BC 4300 bytes