Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 7d8c96446f4daba6…

MALICIOUS

RTF / .DOC

12.0 KB First seen: 2022-03-11
MD5: 61d865a3146022839c682c6129f33c18 SHA-1: d016f606309a92544592573efc2ed061338464fe SHA-256: 7d8c96446f4daba6698edbcd0bfb673afeda511922296470c9c1cf89db1f1ab3
121 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 objects and triggers an objupdate event, indicating an attempt to exploit the Equation Editor vulnerability (CVE-2017-11882). This exploit is known to be used for dropping secondary payloads. No specific family could be identified from the available heuristics.

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_off00001e51.bin
7e19a80a029806a8d48386fbc32cdd15999d2e268e8ed13bfe6422d6c394b75b
rtf-objdata-decoded RTF \objdata at offset 0x1E51 2078 bytes