Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 e3a40941dddaa82e…

MALICIOUS

RTF / .DOC

31.0 KB First seen: 2023-04-11
MD5: b49e17afa43c884a15dcc90f453611ec SHA-1: 00b78d3febc1f8863486063e81412b03c11a6f8f SHA-256: e3a40941dddaa82e73a94ea6a42650594ae6f3de836fd43688ebcee4c78a5f83
140 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, and an \objupdate directive that forces OLE activation. The document body contains a lure instructing the user to 'Enable editing' to view the content, which is a common technique for malware droppers to bypass macro security. The embedded OLE object likely exploits a vulnerability, such as CVE-2017-11882, to execute a malicious payload.

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_off0000501c.bin
37db1df34a70686a7859014945e7734ffc0913f733b3eb77d4c6b7a7b87b9385
rtf-objdata-decoded RTF \objdata at offset 0x501C 1586 bytes