Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 16fd16f1795de27c…

MALICIOUS

RTF / .DOC

169.9 KB
MD5: 43def8eefaaf8cdf55225bffdda8ec38 SHA-1: 9f4ab9578dd5808293afb3aead4691cb162d3b41 SHA-256: 16fd16f1795de27c016a22b16c4db01bf7f2197a91dfc98dc8f7ab9c4e85c464
180 Risk Score

Malware Insights

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

The sample is an RTF document that contains an embedded OLE object. Heuristics indicate a critical vulnerability, CVE-2017-11882, related to the Equation Editor, which is likely exploited for client execution. The presence of ".objupdate" suggests that the OLE object is activated automatically upon opening the document, leading to the execution of the embedded payload. No specific family could be identified, but the exploit vector is clear.

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_off00000693.bin
9c0caa8537599aae7bbd64f577ff616d467da532249edb231e189d096dbd1a3c
rtf-objdata-decoded RTF \objdata at offset 0x693 4180 bytes