Malicious RTF — malware analysis report

Static analysis result for SHA-256 461de8505d91d398…

MALICIOUS

RTF

8.2 KB First seen: 2018-10-07
MD5: 9423c952271ad5a98e3f39253c296319 SHA-1: 61b6239bcc650ccc515fc6421fe52a79f312df24 SHA-256: 461de8505d91d3987619acfdbd636eaafdb787922d80324e61d0ef9e59ad2388
240 Risk Score

Malware Insights

MITRE ATT&CK
T1203 Exploitation for Client Execution T1566.001 Spearphishing Attachment

The RTF file contains embedded OLE object data and specifically triggers heuristics related to the Equation Editor vulnerability (CVE-2017-11882). This exploit allows for arbitrary code execution when the document is opened. The presence of the ".objupdate" directive further indicates an attempt to automatically activate the embedded OLE object, facilitating the exploit.

Heuristics 5

  • Equation Editor CLSID critical CVE likely RTF_EQUATION_EDITOR
    Equation Editor OLE CLSID found inside an OLE object — exploited by CVE-2017-11882 / CVE-2018-0802 / CVE-2018-0798
  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • ClamAV: Doc.Exploit.CVE_2017_11882-6934206-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Exploit.CVE_2017_11882-6934206-0
  • \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

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000003b.bin rtf-objdata-decoded RTF \objdata at offset 0x3B 4155 bytes
SHA-256: 4666a3da7255dec480a10aa15c3601dfdba406cdc05dccc14809d570c3ae470f