Combating Advanced Persistent Threats with Flow-based Security Monitoring

Combating Advanced Persistent Threats
with Flow-based Security Monitoring
Jeffrey M. Wells, CCIE, CISSP
Sr. Systems Engineer
Lancope
Know Your Network, Run Your Business
Thank you for joining. We will begin shortly.

Poll Question
What is your organization’s top security concern?
A. Insider Threats
B. Advanced Persistent Threats (Directed Attacks)
C. Virtualization / Cloud Computing
D. IT Consumerization / User Mobility / BYOD
E. Compliance
2 ©2011 Lancope , Inc. All Rights Reserved. Company Confidential (not for distribution)

What is an Advanced Persistent Threat?

What is an Advanced Persistent Threat?
Examples: “Operation Aurora” against Google and at least 20 other large companies in 2009, the
HBGary attack, the RSA attack against over 700 companies over 2011
• in that the attacker uses the full spectrum of available tools, including social
engineering, to accomplish his or her goals. The toolset and methods mean
these will likely evade traditional signature-based detection methods.
It’s Advanced…
• in that the attacker defines a target and then focuses resources on that target,
rather than casting a net in the dark. This is what makes this type of attack so
dangerous. Rather than playing the odds, one must actively defend oneself
from it.
It’s Persistent…
• this should be self-explanatory.
It’s a Threat…

Anatomy of an APT attack - HBGary
 HBGary was attacked by Anonymous in February 2011 in response to
provocation by an HBGary employee.
 HBGary Federal sought to “out” WikiLeaks and associated Anonymous hacker
organization
 Anonymous finds out and launches full frontal assault on HBGary
 HBGary website defaced, emails stolen, backups deleted,
twitter and LinkedIn accounts hacked, etc.
 Massive damage to HBGary’s reputation
 Cleanup could take weeks or
months
 HBGary vs. Anonymous: Story by Ars Technica
http://arstechnica.com/tech-policy/news/2011/02/anonymous-speaks-the-inside-story-of-the-hbgary-hack.ars

Anatomy of an APT attack - RSA
 In February 2011 RSA was subjected to an attack by Chinese
hackers.
 RSA suffered enormous brand damage and was forced to replace
existing tokens in the field.
 Read more: http://blogs.rsa.com/rivner/anatomy-of-an-attack/
Footnote: this attack was repeated against hundreds of other companies, as revealed last Fall by the FBI.

APTs in the news

APTs are here to stay
 Facts:
• APTs are an evolution of cybercrime. They are the beginnings of truly organized
behavior designed to cost you money.
• APTs are proliferating. There are many many examples, and they target pretty
much every large company.
• APTs evade traditional detection.
• Many companies do not discover that they’ve been targeted until long after it’s
over.

APT characteristics for the investigator
 APT will generally involve:
– Information gathering via social media and Google search. It is via this that the
targets for the social engineering phase are identified.
– Exploit of common vulnerabilities in support of the above.
– Targeted social engineering attacks against identified users.
– Compromise of one or more internal machines and installation of remote control
software of some kind.
– Data mining from the inside.
– Exfiltration of data.
 Network-based APT detection boils down to discovering
the command-and-control connections, the data mining,
and the exfiltration activity. As with all attacks, success is
measured by the time lapsed between attack and
discovery.

APT Survey by Ponemon Institute, June 2010
 “Prevention and detection of advanced threats is difficult. Organizations risk a
costly data breach because detection of an advanced threat takes too long. 80
percent of respondents say it takes a day or longer to detect an advanced
threat and 46 percent say it takes 30 days or longer. This leaves a huge window
of opportunity to steal confidential or sensitive information. In addition, 79
percent believe that advanced threats are very difficult to prevent, detect and
resolve.”
 “The most effective technologies have yet to be deployed. 92 percent of
respondents believe network and traffic intelligence solutions are essential,
very important or important. Yet, only 8 percent say these technologies are
their first choice to detect or prevent an advanced threat. 69 percent of
respondents say that AV and 61 percent of respondents say that IDS are
typically used to detect or discover advanced threats. Yet, 90 percent report
that exploits or malware have either evaded their IDS systems or they are
unsure. 91 percent say that exploits and malware have evaded their AV
systems or they are unsure. The same percentage (91 percent) believes
exploits bypassing their IDS and AV systems to be advanced threats.”

User Behavior
DMZ
Internal
Network
Internet
11
This goes on, day after day…
And then…
FTP to foreign destination.
This is a Behavioral Anomaly

Anomalous Behavior
 If you’re focused solely on a single actor, behavioral anomalies are relatively
simple to spot.
 As the observed population increases, it becomes increasingly difficult to spot
anomalies.
Where’s Waldo?

Brains and Computers
 Our brains happen to be good at focusing on detail or recognizing patterns in
limited datasets but very bad at dealing with huge amounts of rapidly-evolving
data at once.
 Computers, on the other hand, do not suffer from this limitation.

Email interconnection graph
This is a network of devices speaking SMTP. If they
spoke something else it would be trivial to detect –
as long as we were focusing on this network as a
group and not trying to watch all the other systems
that live alongside these devices.

3G
Internet
3G
Internet
Typical Corporate Environment
DMZ
VPN
Internal
Network
Internet
3G
Internet
3G
Internet
15
Even though it seems difficult to
enumerate the protocols and behaviors
on such a network, a statistical system
can do so with ease.

APT Detection Objectives and Requirements
 Objectives:
– Discover APT behavior as rapidly as possible
– Discover compromised machines in my environment
– Discover potential exfiltrations of data
– Some sort of scoring or prioritization of alarms to direct response
 Requirements:
– Need data sources
– Need collection infrastructure
– Need analysis infrastructure
– Need reporting and alerting engine
 Potential data sources:
– SYSLOG, IDS/IPS probes, distributed data capture, SNMP, RMON probes, host AV/AS
agents, host IDS/IPS agents
– Netflow

Data Source Caveats
 SYSLOG: Very painful to parse due to the vast number of different potential messages.
May or may not contain what you need.
 IDS/IPS probes: Expensive to install and maintain, reliance on signature-based
technologies makes them less useful for APT detection.
 Distributed data capture: Extremely expensive to install and maintain, large amount
of hardware required, very inefficient: most of the useful information comes from a
tiny percentage of the gathered data.
 SNMP: Not enough information on its own to be particularly useful, very slow.
 RMON: Expensive to install and maintain, limited support.
 Host agents: Expensive to install and maintain, reliance on signature-based
technologies not particularly useful, proprietary data output difficult to integrate and
correlate, host context limits understanding of network behavior.
 Flow-based technology: May not be supported by all of your network hardware.

3G
Internet
Flow-based monitoring basics
DMZ
VPN
Internal
Network
Internet
NetFlow
3G
Internet
3G
Internet
NetFlow
NetFlow
NetFlow
NetFlow
NetFlow Packets
src and dst ip
src and dst port
start time
end time
mac address
byte count
- more -
FlowCollector

Major advantages of flow-based telemetry
 Fixed and highly-standardized records easy to create, transport, compress and
parse.
 Generated by the network hardware you already own.
 Generation not specifically limited by topology or data rates.
 Simple record types lend themselves to rapid and near-real-time analysis on
even the biggest, busiest networks.
 Most of visibility objectives achievable with no need for probes or signatures.
 Generation technology eliminates evasion techniques. All network traffic will
generate flow data for analysis.
 Can easily be correlated to other data sources to enrich the results.

DMZ
Internet
Atlanta
San Jose
New York
NetFlow
NetFlow
NetFlow
NetFlow
NetFlow
NetFlow
NetFlow
NetFlow
ASR-1000
Cat6k
UCS with
Nexus 1000v
ASA
Cat6k
3925 ISR
3560-X
NetFlow
NetFlow
NetFlow
NetFlow
Lancope NetFlow
Collector
Datacenter
3750-X
Stack(s)
NetFlow
NetFlow
Cat4k
NetFlow
NetFlow
WAN
Example: NetFlow Technology in a Cisco environment

NetFlow at 10G+
21
Lancope
NetFlow
Collector

NetFlow Collection in the WAN
NetFlow Packet
NetFlow Packet
22
Lancope NetFlow
Collector

NetFlow Technology simplified
telephone bill
NetFlow
23

The Science of Flow Analysis
• Lancope specializes in Behavior-based Network Flow Analysis
• Detects attacks by baselining and analyzing network traffic patterns
• Excellent defense in depth strategy to aid in defense of critical assets
• Over 600 customers world-wide
• Designed for the large enterprise
http://netflowninjas.lancope.com
24

Flow-based telemetry
in action

Visibility into “normal” network behavior.
What is all this HTTP traffic?
26

Detection of anomalous behavior. Circa 2003!
27

Manual analysis
Deduplicated Host Groups provide the basis
for many Reports, Baselines, Top N lists,
etc.
28

Manual analysis, continued
5 hour 6 Mbps ssh connection?
29

StealthWatch Threat Indexes – Attack Detection Without Sigs
31
StealthWatch tracks not only the statistical behavior of normal
traffic, but also the behavior of well over a hundred specific
network traffic patterns. Concern points are generated by
anomalous changes in any –and all – of these.
Examples: number of new connections to or from a device.
Connection attempts that go unanswered (common in
scanning). New ports seen. Number of clients for a server or
service. Rejected traffic. Long-lived connections.
StealthWatch also alerts when the concern index itself changes.

Target and specialized protocol tracking
 StealthWatch pays particular attention to hosts “touched” by a host with high
concern.
 StealthWatch creates “Target Index” reporting for these hosts, including
“Touched Hosts” and “Touched Hosts with high CI.”
 StealthWatch has special handling for protocols commonly used for file
sharing.
 StealthWatch has special logic to watch for and alert on “worm behavior”.
All of these are completely automatic, out-of-the-box capabilities of the system.

Host Group tracking
Creating host groups by function, type or location allows the system to easily spot and
track anomalous behavior for hosts with high degrees of inherent predictability. The
system will for example automatically tell you when your Webservers have stopped
behaving like Webservers

Relational Flow Maps
34
The powerful Relational Flow Mapping feature allows you to track the relationships between
your host groups as well as their relationships to external groups whether they are business
partners, Internet hosts, countries, or suspicious hosts from threat feeds. Once the
relationsnip is established, StealthWatch automatically creates a statistical baseline and
applies its powerful anomaly detection logic to the relationship.

Relational Anomaly Detection example: PCI hosts
Secure Zone
35

Custom views match your particular area of interest
Custom charts focusing on particular
alerts related to APT events
Relational flow map to track behavior
between areas of high interest
List of hosts currently creating high
concern
List of internal hosts exhibiting active
scanning behavior
All documents are active – current alerts
shown over objects as callouts in real
time

Drill down from anywhere to any level of detail
Every object is active and can be used as a starting point to drill in for investigation.

Enhanced Application Monitoring
 Accelerates troubleshooting and forensic
investigations
 Quickly differentiate between applications
 Easily determine which applications are causing
performance or security problems
 Displays URL information in flow records
 Identifies hostname of the server and error
messages within the flow
© 2011 Lancope, Inc. All rights reserved.38

21
Botnet - 315,000 nodes, 3 billion connections
39
4/18/2012
Other resources for detection of anomalous behavior

Threat feed correlation and host locking

Putting it all together:
Detection Examples

Bot Detection:
Are there bot infected hosts within the network?

Suspect Data Loss:
Is there any sensitive data being uploaded to the Internet?

Reconnaissance Detection:
What hosts are trying to find resources to compromise?

Quick Recap
• NetFlow analysis gives us APT defense via
A PROVEN, time-honored end-to-end rich view of every conversation
Topology independence
Deep statistical analysis and alerting
Very high performance and scale
• Flow telemetry is available from all over the network …
Routers
Switches
Load Balancers
Firewalls
FlowSensors
Even the virtual network!
• Once you’ve enabled flow collection you can...
Gain deep traffic analysis and network visibility
Detect attacks and network anomalies faster
Investigate incidents and build up operational context
46

Next Steps
47
Contact Lancope:
Jeffrey M. Wells
jwells@lancope.com
Lancope
sales@lancope.com
Lancope Marketing
marketing@lancope.com
Visit Lancope for a live demonstration of
the StealthWatch System @
 InfoSecurity Europe booth F61
 Cisco Live US booth 944

Thank You
 Web
http://www.lancope.com
 Blog
http://netflowninjas.lancope.com
 Twitter
@netflowninjas
 LinkedIn : NetFlow Ninjas
http://www.linkedin.com/groups?about=&gid=2261596&trk=anet_ug_grppro
 NetFlow Ninjas Challenge
http://www.lancope.com/netflow-ninja-quiz

Combating Advanced Persistent Threats with Flow-based Security Monitoring

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