Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 303ccfbd80e2eb33…

MALICIOUS

RTF / .DOC

12.8 KB
MD5: 0d452e494464939460bbbcf8b09a92b7 SHA-1: a3d43a245308ad0aa24d6fc8881a9288ce98c894 SHA-256: 303ccfbd80e2eb33c3be5807929826a99578facbc4ee604b2774fd907bfbcc7f
120 Risk Score

Malware Insights

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

The sample is an RTF document that contains embedded OLE object data. Critical heuristic firings indicate the presence of a known Equation Editor vulnerability (RTF_EQUATION_EDITOR) and that the object is set to update automatically (RTF_OBJUPDATE), which is a common technique for exploiting this vulnerability. The RTF_OBJDATA heuristic further confirms the presence of embedded OLE objects. These factors strongly suggest an exploit targeting the Equation Editor component to achieve arbitrary code execution.

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_off000004f8.bin
00e87bc607eb20b720e534a51814ecf474cf99de551dcb098774332279fc3ed4
rtf-objdata-decoded RTF \objdata at offset 0x4F8 1565 bytes