Malicious RTF — malware analysis report

Static analysis result for SHA-256 d242561774b755f0…

MALICIOUS

RTF

51.6 KB First seen: 2020-06-01
MD5: 247d2d4a7b1c9aa0a3f6c7a9ab576ed5 SHA-1: c6a817954e8c20b9e103641c4762f8949e15c6d0 SHA-256: d242561774b755f0f997a8e21825406f0df5225f1b0e59f0c3b2d7d47b3da07f
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 technique is commonly used to execute arbitrary code, likely to download and run a second-stage payload. The presence of the Ole10Native stream is a strong indicator of 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_off000015ca.bin rtf-objdata-decoded RTF \objdata at offset 0x15CA 14107 bytes
SHA-256: 39eb4d6a08818b70ae335a26856731c581996a3696848a7d2a92c79f9d9b25bf