Malicious RTF — malware analysis report

Static analysis result for SHA-256 b0111ccedd10f06b…

MALICIOUS

RTF

9.9 KB First seen: 2019-05-10
MD5: c1bfd853e41a73176457b50d1e151ccb SHA-1: ab2827959dc385de2ed9dd792a516444f9d6e1f8 SHA-256: b0111ccedd10f06b039d63b04e0bf5fbb52067b92f510d11cf06fb3f7d2bdef5
182 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 Equation Editor and ".objupdate" which forces OLE activation. ClamAV detection confirms this is Rtf.Exploit.CVE_2017_11882-6584355-1, indicating exploitation of a known vulnerability in Equation Editor for client execution. The presence of a benign URL and repetitive text in the document body does not detract from the exploit's primary function.

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
  • ClamAV: Rtf.Exploit.CVE_2017_11882-6584355-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Rtf.Exploit.CVE_2017_11882-6584355-1
  • \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 URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2003/wordml In RTF body
    • http://bit.ly/2R6II39In RTF body

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000005e8.bin rtf-objdata-decoded RTF \objdata at offset 0x5E8 3618 bytes
SHA-256: a3d108626aee46b160722a46a815ff4cc2a0effcaec6aa0c560ca324bdc86d48