Malicious RTF — malware analysis report

Static analysis result for SHA-256 8e353c1f1a7b0dde…

MALICIOUS

RTF

22.6 KB First seen: 2023-06-08
MD5: 39669a47b553f5d6b3ed6b730d7852f9 SHA-1: 74b365ae0dc316eee5de6df5911019cabe512efb SHA-256: 8e353c1f1a7b0ddea3289b04cb2fb2bde6eacb21298cca8a0c2af37081e5be8d
180 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object that leverages the Equation Editor vulnerability (CVE-2017-11882). The object's Ole10Native stream has high entropy, indicating it likely contains a second-stage payload. The heuristic firings strongly suggest 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_off0000067c.bin
a63991344715f0b602ff68653eaf3fe5da2ce1a38075d52267d3428c2400fcbb
rtf-objdata-decoded RTF \objdata at offset 0x67C 4187 bytes