Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 88487a1a199fd2ed…

MALICIOUS

RTF / .DOC

27.3 KB First seen: 2023-06-17
MD5: e0907862b96f0342e3ca578ba753913f SHA-1: 318b5a1509678d55e225d178e05cb154f836854b SHA-256: 88487a1a199fd2edca3ed2c60997116aa4ce1f63f2fba7b68be0ad9b96ca88be
140 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1059.005 PowerShell

The sample is an RTF document that contains an embedded OLE object, specifically targeting the Equation Editor vulnerability. The \objupdate directive indicates an attempt to automatically activate this object upon opening, which is a common method for exploiting client-side vulnerabilities. The document body contains a lure to 'Enable editing', further suggesting a malicious intent to bypass security measures and execute an 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_off00004960.bin
1e52aac1acf1224bef633ee926d80e570296db9ae0adb3e13494bfc6c359a553
rtf-objdata-decoded RTF \objdata at offset 0x4960 1673 bytes