Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 d7b9bbf9d8824ee3…

MALICIOUS

RTF / .DOC

2.62 MB
MD5: d34ed2575bc507c706d1d05a8b4a2ba3 SHA-1: 4e1f51df16c71c6ba2b94805eb0960ef3831c417 SHA-256: d7b9bbf9d8824ee32748b597861cf069998400fb770cb5a54451508dfc8889df
140 Risk Score

Malware Insights

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

The critical RTF_EQUATION_EDITOR heuristic indicates exploitation of a known vulnerability in the Equation Editor component. The presence of OLE object data and the ".objupdate" flag further suggest that embedded objects are being activated to run malicious code. The truncated script content appears to contain obfuscated JavaScript or VBA, likely intended to download and execute a second-stage payload, which is a common technique for initial access and further compromise.

Heuristics 4

  • 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
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000dea.bin
7363b2a4aeb0f9c6cac6846cab3e435730ce90e087fc0e57836fd4a581eeda1c
rtf-objdata-decoded RTF \objdata at offset 0xDEA 61384 bytes
objdata_01_off0003b8ac.bin
bd688238fe4a81b93b1791e1c8455780aa3bc451293f8827d97ccbf101b8d65e
rtf-objdata-decoded RTF \objdata at offset 0x3B8AC 555368 bytes