Squid proxy events for ToR proxies

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Id	90d3f6ec-80fb-48e0-9937-2c70c9df9bad
Rulename	Squid proxy events for ToR proxies
Description	Check for Squid proxy events associated with common ToR proxies. This query presumes the default squid log format is being used. http://www.squid-cache.org/Doc/config/access_log/
Severity	Low
Tactics	CommandAndControl
Techniques	T1090 T1008
Required data connectors	Syslog SyslogAma
Kind	Scheduled
Query frequency	1d
Query period	1d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Syslog/Analytic Rules/squid_tor_proxies.yaml
Version	1.0.3
Arm template	90d3f6ec-80fb-48e0-9937-2c70c9df9bad.json

KQL

let DomainList = dynamic(["tor2web.org", "tor2web.com", "torlink.co", "onion.to", "onion.ink", "onion.cab", "onion.nu", "onion.link",
"onion.it", "onion.city", "onion.direct", "onion.top", "onion.casa", "onion.plus", "onion.rip", "onion.dog", "tor2web.fi",
"tor2web.blutmagie.de", "onion.sh", "onion.lu", "onion.pet", "t2w.pw", "tor2web.ae.org", "tor2web.io", "tor2web.xyz", "onion.lt",
"s1.tor-gateways.de", "s2.tor-gateways.de", "s3.tor-gateways.de", "s4.tor-gateways.de", "s5.tor-gateways.de", "hiddenservice.net"]);
Syslog
| where ProcessName contains "squid"
| extend URL = extract("(([A-Z]+ [a-z]{4,5}:\\/\\/)|[A-Z]+ )([^ :]*)",3,SyslogMessage),
        SourceIP = extract("([0-9]+ )(([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3}))",2,SyslogMessage),
        Status = extract("(TCP_(([A-Z]+)(_[A-Z]+)*)|UDP_(([A-Z]+)(_[A-Z]+)*))",1,SyslogMessage),
        HTTP_Status_Code = extract("(TCP_(([A-Z]+)(_[A-Z]+)*)|UDP_(([A-Z]+)(_[A-Z]+)*))/([0-9]{3})",8,SyslogMessage),
        User = extract("(CONNECT |GET )([^ ]* )([^ ]+)",3,SyslogMessage),
        RemotePort = extract("(CONNECT |GET )([^ ]*)(:)([0-9]*)",4,SyslogMessage),
        Domain = extract("(([A-Z]+ [a-z]{4,5}:\\/\\/)|[A-Z]+ )([^ :\\/]*)",3,SyslogMessage),
        Bytes = toint(extract("([A-Z]+\\/[0-9]{3} )([0-9]+)",2,SyslogMessage)),
        contentType = extract("([a-z/]+$)",1,SyslogMessage)
| extend TLD = extract("\\.[a-z]*$",0,Domain)
| where HTTP_Status_Code == "200"
| where Domain contains "."
| where Domain has_any (DomainList)
| extend AccountName = tostring(split(User, "@")[0]), AccountUPNSuffix = tostring(split(User, "@")[1])

YAML

queryPeriod: 1d
query: |
  let DomainList = dynamic(["tor2web.org", "tor2web.com", "torlink.co", "onion.to", "onion.ink", "onion.cab", "onion.nu", "onion.link",
  "onion.it", "onion.city", "onion.direct", "onion.top", "onion.casa", "onion.plus", "onion.rip", "onion.dog", "tor2web.fi",
  "tor2web.blutmagie.de", "onion.sh", "onion.lu", "onion.pet", "t2w.pw", "tor2web.ae.org", "tor2web.io", "tor2web.xyz", "onion.lt",
  "s1.tor-gateways.de", "s2.tor-gateways.de", "s3.tor-gateways.de", "s4.tor-gateways.de", "s5.tor-gateways.de", "hiddenservice.net"]);
  Syslog
  | where ProcessName contains "squid"
  | extend URL = extract("(([A-Z]+ [a-z]{4,5}:\\/\\/)|[A-Z]+ )([^ :]*)",3,SyslogMessage),
          SourceIP = extract("([0-9]+ )(([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3})\\.([0-9]{1,3}))",2,SyslogMessage),
          Status = extract("(TCP_(([A-Z]+)(_[A-Z]+)*)|UDP_(([A-Z]+)(_[A-Z]+)*))",1,SyslogMessage),
          HTTP_Status_Code = extract("(TCP_(([A-Z]+)(_[A-Z]+)*)|UDP_(([A-Z]+)(_[A-Z]+)*))/([0-9]{3})",8,SyslogMessage),
          User = extract("(CONNECT |GET )([^ ]* )([^ ]+)",3,SyslogMessage),
          RemotePort = extract("(CONNECT |GET )([^ ]*)(:)([0-9]*)",4,SyslogMessage),
          Domain = extract("(([A-Z]+ [a-z]{4,5}:\\/\\/)|[A-Z]+ )([^ :\\/]*)",3,SyslogMessage),
          Bytes = toint(extract("([A-Z]+\\/[0-9]{3} )([0-9]+)",2,SyslogMessage)),
          contentType = extract("([a-z/]+$)",1,SyslogMessage)
  | extend TLD = extract("\\.[a-z]*$",0,Domain)
  | where HTTP_Status_Code == "200"
  | where Domain contains "."
  | where Domain has_any (DomainList)
  | extend AccountName = tostring(split(User, "@")[0]), AccountUPNSuffix = tostring(split(User, "@")[1])  
name: Squid proxy events for ToR proxies
entityMappings:
- fieldMappings:
  - columnName: User
    identifier: FullName
  - columnName: AccountName
    identifier: Name
  - columnName: AccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: SourceIP
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: URL
    identifier: Url
  entityType: URL
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Syslog/Analytic Rules/squid_tor_proxies.yaml
requiredDataConnectors:
- connectorId: Syslog
  dataTypes:
  - Syslog
- connectorId: SyslogAma
  dataTypes:
  - Syslog
description: |
  'Check for Squid proxy events associated with common ToR proxies. This query presumes the default squid log format is being used.
  http://www.squid-cache.org/Doc/config/access_log/'  
kind: Scheduled
version: 1.0.3
queryFrequency: 1d
severity: Low
relevantTechniques:
- T1090
- T1008
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
id: 90d3f6ec-80fb-48e0-9937-2c70c9df9bad

ARM