Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 dd362a4a2078d3c4…

MALICIOUS

RTF / .DOC

35.5 KB First seen: 2023-05-10
MD5: f2881ed757ae5cadc95c24e27e62b1b4 SHA-1: ff02ffee9ca4ca7040f891894172b8a27082642c SHA-256: dd362a4a2078d3c41afbcaee201141dc98a5ce2f2af35968fdbcb89704ace577
140 Risk Score

Malware Insights

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

The sample is an RTF document containing an embedded OLE object, specifically identified as an Equation Editor exploit. The \objupdate directive suggests the object will be activated automatically upon opening, bypassing user interaction. The document body contains a lure instructing the user to 'Enable editing', which is a common tactic to bypass macro security settings and trigger the exploit.

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 1 \objdata section(s) — embedded OLE objects
  • 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_off00004b2d.bin
60b761af95d319fe42f9c0bb666c7d3c01ee2f7784e1427fe13cfdc104fdec02
rtf-objdata-decoded RTF \objdata at offset 0x4B2D 1550 bytes