Malicious RTF — malware analysis report

Static analysis result for SHA-256 1768eeca3dbf15b1…

MALICIOUS

RTF

106.1 KB First seen: 2023-08-15
MD5: f9bd669474401ebe67afbadf8213f322 SHA-1: be70095cd545ebf06ed499fb64fe6ac1bf06a0bd SHA-256: 1768eeca3dbf15b17955ec2e16702f1d3b39f79420e2c218c5f53019d85680cf
160 Risk Score

Malware Insights

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

The RTF file contains an embedded OLE object, specifically identified as an Equation Editor exploit. The document body provides a lure about financial audits, instructing the user to 'Enable editing'. The presence of ".objupdate" and the Equation Editor heuristic strongly suggest the OLE object is designed to be activated, likely to download and execute 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.
  • \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_off00003406.bin
dd7e473d4e5759c4c603560f7a02ed4453140e3359d52102013f38e947533861
rtf-objdata-decoded RTF \objdata at offset 0x3406 1961 bytes