Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 edff50baf76f61fd…

MALICIOUS

RTF / .DOC

1.49 MB
MD5: 1346939d66aaba35fc0b1038500acb57 SHA-1: 069163a5437a681d36bd28db647a3e09cc3c843f SHA-256: edff50baf76f61fd72952a9b613757729994ef745773d7b7ad67f352c302873d
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, likely triggering the exploit. The presence of OLE object data and embedded OLE objects further supports this. The document body contains obfuscated JavaScript-like code which, combined with the exploit, likely serves to download and execute a second-stage payload.

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
daafd94abcdd966deb3816c94e7bd3a4e48e1a9419233af6f5cf5a184056fa32
rtf-objdata-decoded RTF \objdata at offset 0x11DF 54569 bytes
objdata_01_off00032017.bin
d2d324e28f9f3abf7d31268816f242dc5b73a8f28b0fbb08fc6be0000c82040f
rtf-objdata-decoded RTF \objdata at offset 0x32017 322519 bytes