Malicious RTF — malware analysis report

Static analysis result for SHA-256 8239f88d56e5942f…

MALICIOUS

RTF

1.55 MB
MD5: aca68e1e1f97440197d8388e3f9eaafd SHA-1: 7833772ab216db71e84c0271a937215f8e3fc30f SHA-256: 8239f88d56e5942fbb598d1e319ead8e8f30f5804db469e7f82e5cf9134c8ec1
220 Risk Score

Malware Insights

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

The RTF file contains multiple indicators of malicious activity, including OLE object data and specific heuristics pointing to the Equation Editor vulnerability (CVE-2017-11882). The presence of `equatioN.3` as the OLE class strongly suggests exploitation of this known vulnerability. The large amount of hex-encoded data within the OLE object is likely used to hide a second-stage payload. No scripts were extracted, but the RTF structure itself is the attack vector.

Heuristics 5

  • 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 ~1619KB 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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000140e.bin
bef9ac64316c31952c7c4b08c3fde98d77a3953ca422788edbf7c1433c532275		 rtf-objdata-decoded RTF \objdata at offset 0x140E 809906 bytes

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