Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 be51c62fffe26a7e…

MALICIOUS

RTF / .DOC

20.5 KB
MD5: 087db1ca46eeb2ff16bed1451beaa3d6 SHA-1: 01a3f9a9e4a45f404884d790dc7c19a2054188a5 SHA-256: be51c62fffe26a7e4eaa75db472979a53359d4ec131ab1ccf3294e3d752366f8
120 Risk Score

Malware Insights

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

The file is an RTF document containing OLE object data, specifically triggering the Equation Editor vulnerability (RTF_EQUATION_EDITOR). The ".objupdate" directive (RTF_OBJUPDATE) forces the activation of this embedded object, leading to arbitrary code execution. This is a common method for delivering secondary payloads, although no specific payload or download URL was directly extracted from this sample. The attack pattern is consistent with exploiting the Equation Editor to gain initial access.

Heuristics 3

  • 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.
  • 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_off000018f4.bin
42a8e15ea97b529d979ae0e64cca9531281cc6e2d4e2395b570ed76fe79a7b04
rtf-objdata-decoded RTF \objdata at offset 0x18F4 1491 bytes