Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 5742fd195588b7a6…

MALICIOUS

RTF / .DOC

20.6 KB First seen: 2022-08-15
MD5: eb62dc8fce0b5428ed16937d6693d438 SHA-1: 58ce93422e5464b219bfd06306caa6acb0c2b7fd SHA-256: 5742fd195588b7a63f141d1881468123c63eb56579a800537f5b4693d8ab5e6f
200 Risk Score

Malware Insights

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

The sample is an RTF document containing an OLE object that leverages the CVE-2017-11882 vulnerability in Microsoft Equation Editor. This vulnerability is known to be used for delivering malicious payloads, likely through a spearphishing attachment. The embedded OLE object's structure and the heuristic firings strongly indicate exploitation of this specific CVE.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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 2 \objdata section(s) — embedded OLE objects

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00001d6f.bin
78e7699aca67b93de75992e7421a3b999c22b5ded5a6a2684df92d5928c1cf1c
rtf-objdata-decoded RTF \objdata at offset 0x1D6F 3733 bytes