Malicious RTF — malware analysis report

Static analysis result for SHA-256 d829c064723577b2…

MALICIOUS

RTF

16.8 KB First seen: 2018-10-19
MD5: b510c4aec6c91be0d250e8fbbab2f0af SHA-1: 5c8aff720d67e8f9215d4a4d8c35b0a417cebacf SHA-256: d829c064723577b2ed47b4ea4f5e5c327d01a724f28a3a5db99a4d759b673e1c
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 vulnerability is commonly exploited to execute arbitrary code, likely to download and run a secondary payload. The presence of the Ole10Native stream and objdata further confirms the exploitation attempt.

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_off00000cd6.bin rtf-objdata-decoded RTF \objdata at offset 0xCD6 4649 bytes
SHA-256: a51f4d44e09d57adb98b4c08bb72958ba8eb7bc2ad3d60fc1a12965c1b76c61f