Malicious RTF — malware analysis report

Static analysis result for SHA-256 1fa12de49507ef1d…

MALICIOUS

RTF

22.3 KB First seen: 2023-02-25
MD5: ae4e528a6345a9e52b9d59c955042063 SHA-1: 5f4a664f3c0e684f7556433bf94a0f3ac599dc00 SHA-256: 1fa12de49507ef1d0aa763514f564ab1633fa1fdea283c32416893b6f174b3a0
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 exploit is designed to execute arbitrary code, indicating a high likelihood of a second-stage payload delivery. The presence of OLE object data and specific heuristics strongly suggest this attack vector.

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_off00000f5c.bin
8db5c34d2fe8c8bf71156e268ccc812cf732a9ec7170ebe0ba15f226cdc9e287
rtf-objdata-decoded RTF \objdata at offset 0xF5C 4193 bytes