Malicious RTF — malware analysis report

Static analysis result for SHA-256 a688b9dc4e57322d…

MALICIOUS

RTF

35.9 KB First seen: 2023-05-16
MD5: 645352edc9e892b8d3fc1f4237da1374 SHA-1: 56175b22efabaeb2cc6a0445c2a4de3ad059cf16 SHA-256: a688b9dc4e57322d206117cfcd481a4611a9021a92b9406e853e3752ac667fe2
160 Risk Score

Malware Insights

MITRE ATT&CK
T1204 Malicious Link T1059 Command and Scripting Interpreter

The RTF document contains an embedded OLE object, specifically identified as a potential Equation Editor exploit. The presence of \objupdate and SE_ENABLE_LURE heuristics indicates the document is designed to trick the user into enabling editing, which would then activate the embedded object. This strongly suggests an attempt to exploit a known vulnerability, likely CVE-2017-11882, to execute a malicious 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_off000045c4.bin
c48e6563858a824e97a21f29cd542d46df547021e3f2a524236e1905e5be5e20
rtf-objdata-decoded RTF \objdata at offset 0x45C4 1728 bytes