Malicious RTF — malware analysis report

Static analysis result for SHA-256 e04bb348676422be…

MALICIOUS

RTF

25.8 KB First seen: 2023-06-08
MD5: 930ee6aa6ef31ed1b129d72cabf61487 SHA-1: d9de472f318689ad2182d31ada269688e790324c SHA-256: e04bb348676422be5b66ca3f82cb7b093ee08b0eab2230bb03e145565c9e4bb3
180 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object that leverages the CVE-2017-11882 Equation Editor vulnerability. This technique is commonly used to deliver a secondary payload. The presence of `ole10Native` stream and the `CVE_2017_11882_EQUATION_OLE10NATIVE` heuristic firing strongly indicate exploitation of this known vulnerability for initial execution.

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_off000014c1.bin
4a0df5ba3279506b3378368d3937fbe90ccdbba0f9bb542d17f9481c2c132445
rtf-objdata-decoded RTF \objdata at offset 0x14C1 4191 bytes