Suspicious File Creation via Web Server

[rule]
description = """
This rule detects suspicious file uploads to web servers. Attackers may exploit RCE or file upload vulnerabilities to
upload malicious files to web servers to gain/maintain access and to establish a command and control channel.
"""
id = "a67ef648-f04e-475c-8f53-a2db038ee834"
license = "Elastic License v2"
name = "Suspicious File Creation via Web Server"
os_list = ["linux"]
version = "1.0.7"

query = '''
sequence by process.entity_id with maxspan=3s
  [network where event.type == "start" and event.action == "connection_accepted" and not (
     source.ip == null or source.ip == "0.0.0.0" or cidrmatch(
       source.ip, "10.0.0.0/8", "127.0.0.0/8", "169.254.0.0/16", "172.16.0.0/12", "192.0.0.0/24", "192.0.0.0/29",
       "192.0.0.8/32", "192.0.0.9/32", "192.0.0.10/32", "192.0.0.170/32", "192.0.0.171/32", "192.0.2.0/24",
       "192.31.196.0/24", "192.52.193.0/24", "192.168.0.0/16", "192.88.99.0/24", "224.0.0.0/4", "100.64.0.0/10",
       "192.175.48.0/24","198.18.0.0/15", "198.51.100.0/24", "203.0.113.0/24", "240.0.0.0/4", "::1", "FE80::/10",
       "FF00::/8"
     )
   )
  ]
  [file where event.type == "change" and event.action in ("rename", "creation") and 
   file.extension in ("py", "pl", "rb", "elf", "so", "rs", "lua", "jpeg", "md", "sh", "jsp") and (
     user.name in (
      "apache", "www-data", "httpd", "nginx", "lighttpd", "tomcat", "tomcat8", "tomcat9", "ftp", "ftpuser", "ftpd"
     ) or
     user.id in (99, 33, 498, 48)
   ) and (
     file.path : ("/var/www/*", "/tmp/*", "/var/tmp/*", "/dev/shm/*", "/root/*", "/home/*") and
     process.name : (
       "apache", "nginx", "apache2", "httpd", "lighttpd", "caddy", "php-*", "node", "mongrel_rails", "gunicorn",
       "uwsgi", "openresty", "cherokee", "h2o", "resin", "puma", "unicorn", "traefik", "tornado", "hypercorn",
       "daphne", "twistd", "yaws", "webfsd", "httpd.worker", "flask", "rails", "mongrel"
     )
   ) or
   (process.name : ("ruby*", "perl*", "python*", "java") and file.path : "/var/www/*") and
   not (
     file.name in (
       "config-livewaf.php", "pageviews-busy.php", "attack-data.php", "config-synced.php", "packages.php", "README.txt"
     ) or
     file.name like~ "cookie*.txt" or
     file.path like ("/tmp/requestdir/*", "/var/www/html/storage*", "/var/www/*/Cache/*", "/var/www/*/cache/*") or
     file.extension like ("log", "*-*-*", "webm") or
     process.executable like~ "/root/miniconda3/bin/python*"
   )
  ]
'''

min_endpoint_version = "7.15.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"
[[threat.technique.subtechnique]]
id = "T1059.004"
name = "Unix Shell"
reference = "https://attack.mitre.org/techniques/T1059/004/"



[threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1505"
name = "Server Software Component"
reference = "https://attack.mitre.org/techniques/T1505/"
[[threat.technique.subtechnique]]
id = "T1505.003"
name = "Web Shell"
reference = "https://attack.mitre.org/techniques/T1505/003/"



[threat.tactic]
id = "TA0003"
name = "Persistence"
reference = "https://attack.mitre.org/tactics/TA0003/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1071"
name = "Application Layer Protocol"
reference = "https://attack.mitre.org/techniques/T1071/"


[threat.tactic]
id = "TA0011"
name = "Command and Control"
reference = "https://attack.mitre.org/tactics/TA0011/"

[internal]
min_endpoint_version = "7.15.0"