Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e2a2dfac8fb5bd82…

MALICIOUS

RTF / .DOC

1.94 MB First seen: 2022-03-23
MD5: 28c1c712c433808d04ba89a513cbba5e SHA-1: 71e4fcb8f429f2bc6b76834eef9136f9f66d6ae7 SHA-256: e2a2dfac8fb5bd82baddaca6ce0cbd974e2dd63f7d0f2d9a97517000164fe22d
240 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically related to Equation Editor, which is a strong indicator of the CVE-2017-11882 vulnerability. The presence of `RTF_EQUATION_EDITOR` and `CVE_2017_11882_RELATED` heuristics confirms this. The `RTF_EXCESSIVE_HEX` heuristic suggests that the OLE object likely contains a hidden payload. The document body is heavily obfuscated and does not provide clear user-facing content, further supporting the exploit-driven nature of the attack.

Heuristics 6

  • Equation Editor OLE1 native payload — CVE-2017-11882 related critical CVE related CVE_2017_11882_RELATED
    RTF decodes to an OLE1 Equation.3 embedded object whose native data is large and payload-like, and \objupdate requests automatic activation. This is the delivery shape used by Equation Editor RCE documents such as CVE-2017-11882/CVE-2018-0802, but the malformed MTEF record needed for exact attribution was not recovered.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \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.
  • Large hex data blocks in OLE object high RTF_EXCESSIVE_HEX
    RTF contains ~2028KB of hex-encoded data inside \objdata sections — may hide a payload
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \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_off00000779.bin
650c825cc04e134db20125e1f0893b40e2bebb00ca62db76c110572d0c7d0cfe		 rtf-objdata-decoded RTF \objdata at offset 0x779 1014310 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.