Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 b167e5551463cb7d…

MALICIOUS

RTF / .DOC

31.8 KB First seen: 2023-07-04
MD5: eb7890f4d649ea93e759dcf810fa3d26 SHA-1: 7107d2966eccd5ade43403f5bc7ef9aa9375338c SHA-256: b167e5551463cb7d1ad2e96f6b4a31ee02d3ba879974719de3c70f3db04758a0
160 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a split Equation Editor ProgID, indicating an attempt to exploit a known vulnerability. The \objupdate directive forces OLE activation, and the document body contains a lure instructing the user to 'Enable editing'. This combination suggests the file is designed to exploit the Equation Editor vulnerability to execute a malicious payload upon opening.

Heuristics 5

  • 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 1 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00004505.bin
c6da687cdc9a6fa9c28ef205da077be44c4ae25b1ad5f64a71ed719e95ed0d65
rtf-objdata-decoded RTF \objdata at offset 0x4505 1575 bytes