Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 6408cd34c007b7f2…

MALICIOUS

RTF / .DOC

98.1 KB
MD5: d39d33fe5e361cf01ec9ee3c9b6e09df SHA-1: 8f929399c1bcb09b277bcbaf4417541ff382c79d SHA-256: 6408cd34c007b7f21f1e0e384d7d201dd3f3fad0373e3ef73adba69f44349b96
180 Risk Score

Malware Insights

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

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, allowing the attacker to deliver a secondary payload. The presence of RTF_OBJDATA, RTF_OBJEMB, and RTF_OLE10NATIVE_STREAM heuristics strongly indicates this exploit.

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_off000017cb.bin
3ed88378d06de01b2567a53b0ae3696f07b76e0435b584e757b16b7fd8d407ae
rtf-objdata-decoded RTF \objdata at offset 0x17CB 4270 bytes