Malicious RTF — malware analysis report

Static analysis result for SHA-256 ed248657afc15600…

MALICIOUS

RTF

48.8 KB First seen: 2023-08-02
MD5: bc89a42094fac06d565983f94cb4fa2a SHA-1: d7a9a95e4a4b3c4a1e60262fece5e041f18c002c SHA-256: ed248657afc15600a6b8e5b9cfa94203f9bfeda0ebd1a3007356e99836adeddf
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF file containing an OLE object with a split Equation Editor ProgID, indicating exploitation of CVE-2017-11882. The document body contains a lure instructing the user to 'Enable editing', a common tactic for macro-based malware. The presence of ".objupdate" further suggests automatic activation of the embedded OLE object, likely to trigger the exploit and download a secondary payload.

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.
  • Automatically linked OLE object high RTF_OBJAUTLINK
    RTF contains \objautlink — an automatically linked OLE object surface that can be updated or activated when Word opens the document.
  • \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_off0000353b.bin
1484db1359a6c16fa8f89cee9a873cc8f68325ddb68f1e309043e3180ac24923
rtf-objdata-decoded RTF \objdata at offset 0x353B 1689 bytes