Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 27196e9eaf31ab1c…

MALICIOUS

RTF / .DOC

28.1 KB First seen: 2023-03-27
MD5: a14eb8db11d9222b2e08ab4b9787ce0b SHA-1: 728cbdf334d8133c1c3e6d638e0f94e5354e316d SHA-256: 27196e9eaf31ab1cbc64641706392b8748571eaa19dcfb419396ce1464910558
160 Risk Score

Malware Insights

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

The RTF document contains an embedded OLE object with a specific Equation Editor ProgID, a known indicator of exploit attempts. The \objupdate directive forces OLE activation, and the document body includes a lure to 'Enable editing', strongly suggesting an attempt to exploit vulnerabilities like CVE-2017-11882. The primary goal is likely to execute a second-stage payload via the exploited vulnerability.

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_off00004238.bin
b0a794f64f0b827f704a2d65965d3ddc93eeffad15b1e2e6d9d3ecabee0e9c80
rtf-objdata-decoded RTF \objdata at offset 0x4238 1592 bytes