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Cisco Umbrella DNS

Overview

Cisco Umbrella offers flexible, cloud-delivered security. It combines multiple security functions into one solution, so that protection can be extended to devices, remote users, and distributed locations anywhere.

The following Sekoia.io built-in rules match the intake Cisco Umbrella DNS. This documentation is updated automatically and is based solely on the fields used by the intake which are checked against our rules. This means that some rules will be listed but might not be relevant with the intake.

SEKOIA.IO x Cisco Umbrella DNS on ATT&CK Navigator

Cisco Umbrella Threat Detected

Cisco Umbrella has detected a malicious traffic categorized as malware, phishing or adware.

  • Effort: intermediate
Cryptomining

Detection of domain names potentially related to cryptomining activities.

  • Effort: master
Dynamic DNS Contacted

Detect communication with dynamic dns domain. This kind of domain is often used by attackers. This rule can trigger false positive in non-controlled environment because dynamic dns is not always malicious.

  • Effort: master
Exfiltration Domain

Detects traffic toward a domain flagged as a possible exfiltration vector.

  • Effort: master
Remote Access Tool Domain

Detects traffic toward a domain flagged as a Remote Administration Tool (RAT).

  • Effort: master
SEKOIA.IO Intelligence Feed

Detect threats based on indicators of compromise (IOCs) collected by SEKOIA's Threat and Detection Research team.

  • Effort: elementary
Sekoia.io EICAR Detection

Detects observables in Sekoia.io CTI tagged as EICAR, which are fake samples meant to test detection.

  • Effort: master
Sliver DNS Beaconing

Detects suspicious DNS queries known from Sliver beaconing

  • Effort: intermediate
TOR Usage Generic Rule

Detects TOR usage globally, whether the IP is a destination or source. TOR is short for The Onion Router, and it gets its name from how it works. TOR intercepts the network traffic from one or more apps on user’s computer, usually the user web browser, and shuffles it through a number of randomly-chosen computers before passing it on to its destination. This disguises user location, and makes it harder for servers to pick him/her out on repeat visits, or to tie together separate visits to different sites, this making tracking and surveillance more difficult. Before a network packet starts its journey, user’s computer chooses a random list of relays and repeatedly encrypts the data in multiple layers, like an onion. Each relay knows only enough to strip off the outermost layer of encryption, before passing what’s left on to the next relay in the list.

  • Effort: master

Event Categories

The following table lists the data source offered by this integration.

Data Source Description
DNS records DNS queries are fully analyzed
Network device logs DNS queries logged by Umbrella DNS

Event Samples

Find below few samples of events and how they are normalized by Sekoia.io.

{
    "message": " \"2021-02-21 15:30:49\",\"CORP - IP INTERNET\",\"CORP - IP INTERNET\",\"1.1.1.1\",\"1.1.1.1\",\"Blocked\",\"1 (A)\",\"NOERROR\",\"something.net\",\"DNS Tunneling VPN\",\"Networks\",\"Networks\",\"DNS Tunneling VPN\"",
    "event": {
        "outcome": "success"
    },
    "@timestamp": "2021-02-21T15:30:49Z",
    "action": {
        "name": "DNS query",
        "outcome": "success",
        "properties": {
            "Categories": "DNS Tunneling VPN"
        },
        "target": "network-traffic",
        "type": "blocked"
    },
    "dns": {
        "question": {
            "name": "something.net",
            "registered_domain": "something.net",
            "top_level_domain": "net",
            "type": "A"
        },
        "response_code": "NOERROR",
        "size_in_char": "13",
        "type": "query"
    },
    "related": {
        "hosts": [
            "something.net"
        ],
        "ip": [
            "1.1.1.1"
        ],
        "user": [
            "CORP - IP INTERNET"
        ]
    },
    "source": {
        "address": "1.1.1.1",
        "ip": "1.1.1.1",
        "nat": {
            "ip": "1.1.1.1"
        }
    },
    "user": {
        "name": "CORP - IP INTERNET"
    }
}
{
    "message": " \"2020-06-12 14:29:47\",\"client\",\"client,FRBCORP\",\"1.1.1.1\",\"2.2.2.2\",\"Allowed\",\"1 (A)\",\"NOERROR\",\"client group\",\"Software/Technology,Business Services,Infrastructure,SaaS and B2B,Science and Technology,Application\",\"AD Users\",\"AD Users,Roaming Computers\",\"\"",
    "event": {
        "outcome": "success"
    },
    "@timestamp": "2020-06-12T14:29:47Z",
    "action": {
        "name": "DNS query",
        "outcome": "success",
        "properties": {
            "Categories": "Software/Technology,Business Services,Infrastructure,SaaS and B2B,Science and Technology,Application"
        },
        "target": "network-traffic",
        "type": "allowed"
    },
    "dns": {
        "question": {
            "name": "client group",
            "type": "A"
        },
        "response_code": "NOERROR",
        "size_in_char": "12",
        "type": "query"
    },
    "related": {
        "hosts": [
            "client group"
        ],
        "ip": [
            "1.1.1.1",
            "2.2.2.2"
        ],
        "user": [
            "client"
        ]
    },
    "source": {
        "address": "1.1.1.1",
        "ip": "1.1.1.1",
        "nat": {
            "ip": "2.2.2.2"
        }
    },
    "user": {
        "name": "client"
    }
}
{
    "message": " \"2020-06-12 14:29:48\",\"ERT - IP INTERNET\",\"ERT - IP INTERNET\",\"1.1.1.1\",\"1.1.1.1\",\"Allowed\",\"Other\",\"NXDOMAIN\",\"_ldap._tcp.dc._msdcs.subdomain.corp.intra.\",\"\",\"Networks\",\"Networks\",\"\"",
    "event": {
        "outcome": "failure"
    },
    "@timestamp": "2020-06-12T14:29:48Z",
    "action": {
        "name": "DNS query",
        "outcome": "failure",
        "outcome_reason": "NXDOMAIN",
        "target": "network-traffic",
        "type": "allowed"
    },
    "dns": {
        "question": {
            "name": "_ldap._tcp.dc._msdcs.subdomain.corp.intra.",
            "subdomain": "_ldap._tcp.dc._msdcs.subdomain.corp"
        },
        "response_code": "NXDOMAIN",
        "size_in_char": "42",
        "type": "query"
    },
    "related": {
        "hosts": [
            "_ldap._tcp.dc._msdcs.subdomain.corp.intra."
        ],
        "ip": [
            "1.1.1.1"
        ],
        "user": [
            "ERT - IP INTERNET"
        ]
    },
    "source": {
        "address": "1.1.1.1",
        "ip": "1.1.1.1",
        "nat": {
            "ip": "1.1.1.1"
        }
    },
    "user": {
        "name": "ERT - IP INTERNET"
    }
}
{
    "message": "\"2024-03-04 11:17:25\",\"Firstname LASTNAME (firstname.lastname@corp.com)\",\"Firstname LASTNAME \n(firstname.lastname@corp.com),FR01-MDBBC-L029.hdb.int,CORP_RANGE_01,CORP\",\"10.1.1.1\",\"80.1.1.1\",\"Allowed\",\"1 (A)\",\"NXDOMAIN\",\"10.1.1.1_1.\",\"\",\"AD Users\",\"AD Users,AD \nComputers,Internal Networks,Sites\",\"\"",
    "event": {
        "outcome": "failure"
    },
    "@timestamp": "2024-03-04T11:17:25Z",
    "action": {
        "name": "DNS query",
        "outcome": "failure",
        "outcome_reason": "NXDOMAIN",
        "target": "network-traffic",
        "type": "allowed"
    },
    "dns": {
        "question": {
            "name": "10.1.1.1_1.",
            "subdomain": "10.1.1",
            "type": "A"
        },
        "response_code": "NXDOMAIN",
        "size_in_char": "11",
        "type": "query"
    },
    "related": {
        "hosts": [
            "10.1.1.1_1."
        ],
        "ip": [
            "10.1.1.1",
            "80.1.1.1"
        ],
        "user": [
            "Firstname LASTNAME (firstname.lastname@corp.com)"
        ]
    },
    "source": {
        "address": "10.1.1.1",
        "ip": "10.1.1.1",
        "nat": {
            "ip": "80.1.1.1"
        }
    },
    "user": {
        "name": "Firstname LASTNAME (firstname.lastname@corp.com)"
    }
}
{
    "message": " \"2024-01-15 17:29:16\",\"CORP - IP INTERNET\",\"CORP - IP INTERNET\",\"1.1.1.1\",\"1.1.1.1\",\"Allowed\",\"1 (A)\",\"NOERROR\",\"emea.corp.\",\"\",\"Networks\",\"Networks\",\"\"",
    "event": {
        "outcome": "success"
    },
    "@timestamp": "2024-01-15T17:29:16Z",
    "action": {
        "name": "DNS query",
        "outcome": "success",
        "target": "network-traffic",
        "type": "allowed"
    },
    "dns": {
        "question": {
            "name": "emea.corp.",
            "subdomain": "emea",
            "type": "A"
        },
        "response_code": "NOERROR",
        "size_in_char": "10",
        "type": "query"
    },
    "related": {
        "hosts": [
            "emea.corp."
        ],
        "ip": [
            "1.1.1.1"
        ],
        "user": [
            "CORP - IP INTERNET"
        ]
    },
    "source": {
        "address": "1.1.1.1",
        "ip": "1.1.1.1",
        "nat": {
            "ip": "1.1.1.1"
        }
    },
    "user": {
        "name": "CORP - IP INTERNET"
    }
}
{
    "message": " \"2024-03-12 09:09:48\",\"CD111\",\"CD111\",\"1.1.1.1\",\"1.1.1.1\",\"Allowed\",\"1 (A)\",\"NOERROR\",\"substrate.office.com.\",\"Software/Technology,Webmail,Business Services,Allow List,Organizational Email,Application,Web-based Email,Computers and Internet\",\"Anyconnect Roaming Client\",\"Anyconnect Roaming Client\",\"Allow List\"",
    "event": {
        "outcome": "success"
    },
    "@timestamp": "2024-03-12T09:09:48Z",
    "action": {
        "name": "DNS query",
        "outcome": "success",
        "properties": {
            "Categories": "Software/Technology,Webmail,Business Services,Allow List,Organizational Email,Application,Web-based Email,Computers and Internet"
        },
        "target": "network-traffic",
        "type": "allowed"
    },
    "dns": {
        "question": {
            "name": "substrate.office.com.",
            "registered_domain": "office.com",
            "subdomain": "substrate",
            "top_level_domain": "com",
            "type": "A"
        },
        "response_code": "NOERROR",
        "size_in_char": "21",
        "type": "query"
    },
    "related": {
        "hosts": [
            "substrate.office.com."
        ],
        "ip": [
            "1.1.1.1"
        ],
        "user": [
            "CD111"
        ]
    },
    "source": {
        "address": "1.1.1.1",
        "ip": "1.1.1.1",
        "nat": {
            "ip": "1.1.1.1"
        }
    },
    "user": {
        "name": "CD111"
    }
}

Extracted Fields

The following table lists the fields that are extracted, normalized under the ECS format, analyzed and indexed by the parser. It should be noted that infered fields are not listed.

Name Type Description
@timestamp date Date/time when the event originated.
action.properties.Categories keyword
action.target keyword the target of the action
dns.question.name keyword The name being queried.
dns.question.type keyword The type of record being queried.
dns.response_code keyword The DNS response code.
dns.size_in_char keyword
dns.type keyword The type of DNS event captured, query or answer.
source.ip ip IP address of the source.
source.nat.ip ip Source NAT ip
user.name keyword Short name or login of the user.

Configure

This setup guide will show you how to forward logs produced by CISCO Umbrella service to Sekoia.io by means of an Rsyslog transport channel.

Collect proxylogs files and send them to rsyslog

After configuring Umbrella Log Management with AWS S3, the logs you download will be gzipped CSVs in appropriate subfolder with the following naming format:

dnslogs/<year>-<month>-<day>/<year>-<month>-<day>-<hour>-<minute>.csv.gz

To send these logs to Sekoia.io, we suggest the use of the logger Unix command. For each unzipped file, use the following command line:

logger -t dnslogs -f <YYYY>-<MM>-<DD>-<hh>-<mm>-<xxxx>.csv

Configure the Rsyslog server

Please consult the Rsyslog Transport documentation to forward these logs to Sekoia.io.

Further Readings