Malicious RTF — malware analysis report

Static analysis result for SHA-256 809128ef8b8da11d…

MALICIOUS

RTF

10.3 KB First seen: 2022-07-02
MD5: fd1077af257671250e666d07e99565a1 SHA-1: 46daa89abba5fa2f0bfbefabc070fc993311f005 SHA-256: 809128ef8b8da11d359562f80072de45d2406921306ae029d4c6aba360c9583d
262 Risk Score

Heuristics 7

  • 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.
  • Equation Editor shellcode downloads a second-stage payload critical OLE_MTEF_SHELLCODE_DOWNLOAD_URL
    The shellcode reached by the Equation Editor overflow resolves download/exec APIs (URLDownloadToFile / ShellExecute / WinExec) and fetches a second-stage payload. The download URL was recovered from the Equation Native stream — directly when the shellcode is plaintext, or by emulating its self-decoding stub. An integer-encoded host (e.g. http://000030000706151) is normalised to its dotted-quad form and both spellings are surfaced as IOCs.
  • \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
  • 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://logins.kl.com.ua/2.msi In RTF body
    • http://000030000706151In RTF body
    • http://192.3.140.105Decoded from obfuscated IP host (000030000706151)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000008f6.bin rtf-objdata-decoded RTF \objdata at offset 0x8F6 3627 bytes
SHA-256: 4d44d3ad12ca30122a080381354861edf5f064e86b8de32f43fa9071068e886e