Security Events correlation with ESPER

Security events correlation
with
Nikolay Klendar
bsploit gmail.com

Complex Event Processing (correlation) * - is event processing that combines data from multiple
sourcesto infer events or patterns that suggest more complicated circumstances.
INTRO
*Wikipedia

Library used for development
Java, .NET
Processes event STREAMS of predefined types.
Esper does not parse events!
Processing rules (correlation rules) are defined with
Event Processing Language (EPL) similar to SQL

Network scan detection
Type event:
timestamp:string
type: string
src_ip: string
dst_ip: string
src_port:int
dst_port: int
bytes_sent: int
bytes_recieved: int
login: string
Allowed
monitoring
systmes
Annotation All dst_ip
within 30 sec
@Name('Scan')
SELECT src_ip,window(dst_ip)
FROM event (type='firewall'
AND src_ip NOT IN ('10.0.0.1','10.0.0.2')
).win:time(30 sec) /*sliding time window*/
GROUP BY src_ip
HAVING count(distinct dst_ip) > 50
output first every 1 hour /*1 event per hour*/

Worm spreading detection
INSERT INTO scanning
SELECT src_ip,window(dst_ip) targets
FROM event().win:time(10 min).std:unique(dst_ip)
GROUP BY src_ip
HAVING count(distinct dst_ip)>50;
{ src_ip='10.0.0.1',
targets=['192.168.0.1',
'192.168.0.2',…,'192.168.0.254']}
{ src_ip='192.168.0.2',
targets=['192.167.0.1','192.167.0
.2',…,'192.167.0.254']}
@Name('warm_spreading')
SELECT a.src_ip,b.src_ip,b.targets
FROM pattern[
every a=scanning -> b=scanning (
b.src_ip!=a.src_ip AND
Arrays.asList(a.targets).contains(b.src_ip)
) WHERE timer:within(1 min) ];
{a.src_ip='10.0.0.1',
b.src_ip='192.168.0.2',
b.targets=[' 192.167.0.2 ',…,
'192.167.0.2 ',' 192.167.0.2 ']}

Money laundering detection
@Name('obnal')
SELECT a.transaction,a.clientid,a.amount income,
c.sumOf(i=>i.amount)+b.amount total
FROM PATTERN[
EVERY a=event(transaction like 'card_income') ->
b=event(b.clientid=a.clientid AND transaction = 'card_outcome')
WHERE timer:within(3 hour) ->
( [3: ] c=event(c.clientid=a.clientid AND transaction = 'card_outcome' )
until timer:interval(20 min) )
]
Total money transferred to card
Total outcome

Join & enrichment
SELECT S.src_ip, S.targets, L.login,L.last_seen
FROM scanning.std:lastevent() as S
LEFT OUTER JOIN LoginsIP L on L.ip = S.src_ip
GROUP BY S.src_ip
output first every 1 hour;
CREATE WINDOW
LoginsIP.std:unique(ip) as (ip string, login string, last_seen string);
INSRT INTO LoginsIP
SELECT src_ip as ip, login.toLowerCase() as login, timestamp as last_seen
FROM Event(
type='windows' AND eventid='4624' AND src_ip IS NOT NULL
AND login IS NOT NULL AND login!='ANONYMOUS LOGON'
AND login NOT LIKE '%$' );
{
S.src_ip='10.0.0.1',
L.login='ivanov',
L.last_seen='17.11.2015 12:00:00'
S.targets=[' 192.167.0.2 ',…,
'192.167.0.2 ',' 192.167.0.2 ']
}

Integration with external sources
SELECT src_ip from event(type='firewall') as fw,
SQL:mysql ['select tornode_ip from tor_nodes'] as tor
where fw.src_ip=tor.tornode_ip

Building user profile
create window
loginProfileASN.win:keepall()
(login string,param string,value
string,v_count long)
create window
loginProfileTotal.win:keepall()
(login string,param string,total long)
ON EVENT() e
MERGE loginProfileASN p
where p.login=e.login and
p.value=(e.geoip('asn')).toString()
when not matched
then insert select login,'ASN' param,
geoip('asn') value,1L v_count
when matched
then update set p.v_count = p.v_count+1
ON EVENT() e
MERGE loginProfileTotal p
where p.login=e.login
when not matched
then insert select login,'ASN' param, 1L
total
when matched
then update set p.total = p.total+1

Deviation from profile
SELECT e.login,e.geoip('asn') asn, e.src_ip,
v.v_count count,t.total, cast((100-100*v.v_count/t.total),int) score
FROM event().std:lastevent() e, loginProfileASN v,
loginProfileTotal t
where v.login=e.login and v.value=(e.geoip('asn')).toString()
and t.login = e.login
and (100-100*v.v_count/t.total)>97

CorReactive and integration with ELK
Logstash config
output {
redis {
host => "127.0.0.1"
db => 0
data_type => "list "
batch => true
batch_events=>500
key => "events”
codec => json
}
}
CorReactive config
Collect events
"inputs":[
{
"type": "redis",
"config":{
"host": "localhost",
"port": 6379,
"db": 0,
"queue":"events",
"batch_count":500,
"reconnect_timeout":60
}
}
]
CorReactive config
Return alerts
"outputs":[
{
"type":"redis",
"id":1,
"config":{
"host": "localhost",
"queue":"alerts",
"port": 6379,
"db": 0,
"reconnect_timeout":60,
"batch_count" :1
}
}
]

CorReactive configuration steps
1. conf/types:
Extend base event type “event”, add new fields
2. conf/modules:
Add new EPL modules (correlation rules)
If one module depends on another use special directive:
uses dependent_module; http://goo.gl/9pvlIj
3. Configure inputs and outputs

CorReactive special annotations
Alert generation to output channel
@Alert(name='newalert',outID=1)
Save data from named window to disk every 5 minutes.
Saved data is automatically restored to named window during loading stage
@Persist
Named window data reloading every 5 minutes from csv file
located in var/winload
@Load(file="data.csv",format="csv",delim="; ")
Dynamically alert enrichment with data from external command output
or on demand query. Enrichment of enrichment is supported.
@Enrich(dst="eLogin",type="window", param="select src_ip from loginip where
login='%{login}'")
@Enrich(dst="nsresult",type="cmd",param="nslookup %{eLogin}")

REST API
Send event in JSON format
POST /api/events
View all registered modules
GET /api/modules/registered
View all registered Esper statements
or queries
GET api/modules/statements
Reload data in named window
POST /api/window/reload/{moduleName}/{winName}
Deploy all modules
POST api/modules/deploy
Module deletion
DELETE /api/modules
Module syntax validation
POST api/modules/validate
Do on demand query
POST /api/query

Links
Esper docs
http://www.espertech.com/esper/documentation.php
Solution patterns with description
http://www.espertech.com/esper/solution_patterns.php
EPL editor and debugger
http://esper-epl-tryout.appspot.com/epltryout/mainform.html
CorReactive engine (special for ZeroNights 2015)
http://correactive.sourceforge.net/

Security Events correlation with ESPER

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