SUSP_Doc_RTF_ExternalResource_May22

rule SUSP_Doc_RTF_ExternalResource_May22 {
   meta:
      description = "Detects a suspicious pattern in RTF files which downloads external resources as seen in CVE-2022-30190 / Follina exploitation"
      author = "Tobias Michalski, Christian Burkard"
      date = "2022-05-30"
      modified = "2022-05-31"
      reference = "https://doublepulsar.com/follina-a-microsoft-office-code-execution-vulnerability-1a47fce5629e"
      score = 70
      id = "71bb97e0-ec12-504c-a1f6-25039ac91c86"
   strings:
      $s1 = " LINK htmlfile \"http" ascii
      $s2 = ".html!\" " ascii
   condition:
      uint32be(0) == 0x7B5C7274 and
      filesize < 300KB and
      all of them
}