Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 ef25940acecd4fd9…

MALICIOUS

RTF / .DOC

1.49 MB
MD5: ec733578c8fccf0e3930ddcb2b337228 SHA-1: df8b20801a5ee07f8de71679bb434c94858b0f9e SHA-256: ef25940acecd4fd916e53386f63b8fb69102f2f13e2b7b9e89f64775da9afa08
140 Risk Score

Malware Insights

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

The critical RTF_EQUATION_EDITOR heuristic indicates the file exploits a known vulnerability in the Equation Editor component. The RTF_OBJUPDATE heuristic suggests that the embedded OLE object is designed to be activated automatically, triggering the exploit. The presence of OLE object data and the RTF structure strongly suggest a malicious document designed to deliver a payload, likely via a downloaded second stage, although no specific URLs were extracted.

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_off000011df.bin
1edfe5913b3c022dbb29b7a59f713eef03ddf25888ec68230ded6856254c2903
rtf-objdata-decoded RTF \objdata at offset 0x11DF 54814 bytes
objdata_01_off00032201.bin
d2d324e28f9f3abf7d31268816f242dc5b73a8f28b0fbb08fc6be0000c82040f
rtf-objdata-decoded RTF \objdata at offset 0x32201 322519 bytes