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Advanced Persistent Threat Activity Exploiting Managed Service Providers

December 11, 2018

The National Cybersecurity and Communications Integration Center has been tracking attacks on global Managed Service Providers (MSP) from Advanced Persistent Threat actors since 2016. Targets of these attacks spread across Information Technology (IT), Energy, Healthcare, Public Health, Communications, and Manufacturing industries.

Managed Service Providers offer remote management of their customer’s IT and Networked Infrastructure. Due to the scalability and cost savings of using an MSP, many companies have adopted this form of service. To provide effective management of their network, MSPs are often given complete access to the customer’s network, and potentially have access to customer data.

By nature, MSPs will have more than one customer. If a security breach occurs in the MSP, this will potentially place multiple organizations at risk. MSPs also need to create additional accounts on the customer’s network with elevated privileges. These additional accounts increase the number of avenues available for attack. In addition, the elevated access of these accounts can expose both the MSP and client company, which requires security measures to be proactively taken on both sides.

Advanced Persistent Threat attackers will target legitimate management resources to make the attack look as close to normal day-to-day operations as possible. Since logs are created for most actions made on a network, using expected operations in a malicious way becomes harder to detect. If the attacker can gain access to administrative level user credentials, they can access features and services of various equipment and system tools. For example, if the servers being used contain penetration testing tools, these tools can be used in a malicious way to find additional weaknesses in the network. Additional legitimate, built-in services can then be used to extract data out of the network without raising any red flags to administrators.


View our use case on how to gain visibility during a data breach!

Addressing Attacks on a Managed Service Provider

A successful network intrusion will likely result in severe impacts to the organization, including loss of proprietary information, disruption to regular business operations, financial losses, and harm to the organization’s reputation. Additionally, certain industries must comply with various levels of regulations (HIPAA, PCI, GDPR). If a breach occurs, there are often substantial fines levied against the company depending on the damage to customer information.

Detection

A solution starts with detection of the incident. Centralized log collection appliances should be deployed in the organization. With a centralized log solution, the log is kept in a separate location than the compromised appliance which prevents alterations being made to the local log file. Centralization of logs and using an appliance like a SIEM allows a baseline of normal log activity to be created across the entire network. If a breach occurs, this increases the chances of an alert being created when a legitimate service starts acting in an unexpected way.

Response

An organization’s ability to rapidly respond to and recover from an incident starts with the creation of an incident response program. An incident response plan should include the order of steps to take so that regardless of the issues that could arise, everyone is working on the same important issues instead of scrambling and working on smaller, low-priority tasks.

Committing to an effort that secures the endpoint and network infrastructure: prevention is less costly and more effective than reacting after an incident.  Proactively place security measures and monitoring in place. This is best accomplished with the use of a Network TAP sending data to both security and network monitoring tools.

Recommendations to Mitigate Risk
MSP customers should be aware of the risks that are generated by using an MSP. The customers should be aware of exactly what the MSP needs access to and address these accessibility needs in a manner that gives only the control required.

  • Ensure MSP accounts are not assigned to administrator groups. MSP accounts should be limited to what they need access to manage.  If the account gets compromised, this greatly limits the areas that can be affected.

  • Ensure MSP account passwords adhere to organizational policies and password policies for complexity, expiration dates, and how many new passwords must be used before an old one can be used again.

  • Restrict MSP accounts by time and/or date. This way, if the customer no longer wishes to use the MSP, the account will be locked out in the event it was forgotten about.

  • Centralize system logs to prevent alterations being made to the local file in case of a breach. If a breach occurs, this increases the chances of an alert being created when a legitimate service starts acting in an unexpected way.

  • Configure these central logs to store over one year of log data and establish a log review process.

  • Install and configure a Security Information and Event Management (SIEM) tool to take in logs and network flows for analysis.

  • Create a baseline for system and network behavior by using TAPs and aggregation devices at key points in the network.

  • The best way to monitor traffic is by using a TAP. Let the security appliance focus on security instead of generating SPAN/Mirrored traffic. TAPs will grab 100% of both directions of traffic and send it to a security monitoring tool.

  • Ensure internal and external DNS queries are performed by dedicated servers. Keep DNS locked down and internal, which helps prevent an attacker from intercepting the DNS request and redirecting internet traffic.

  • Restrict access to unauthorized public file shares. DLP appliances will help recognize and stop unapproved exporting of data. Bypass TAPs can ease the implementation of DLP systems into a network.

  • Periodically review network device environments and configurations.

  • Review privileged account groups and disable inactive groups.

There is no single solution to protecting and defending a network. By closely following industry best practices and standards for your security and monitoring stack, you can increase the odds of successfully identifying an intrusion, stopping the attack, and disrupting malicious activity. The ultimate goal is to make it as difficult as possible for an attacker to successfully breach your network, while forcing them to use methods that are easier to detect.

[Want to dig deeper into how to gain full visibility during an instant response data breach? Check out our use case with the Cyber Defense Group.]

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Heartbeats Packets Inside the Bypass TAP

If the inline security tool goes off-line, the TAP will bypass the tool and automatically keep the link flowing. The Bypass TAP does this by sending heartbeat packets to the inline security tool. As long as the inline security tool is on-line, the heartbeat packets will be returned to the TAP, and the link traffic will continue to flow through the inline security tool.

If the heartbeat packets are not returned to the TAP (indicating that the inline security tool has gone off-line), the TAP will automatically 'bypass' the inline security tool and keep the link traffic flowing. The TAP also removes the heartbeat packets before sending the network traffic back onto the critical link.

While the TAP is in bypass mode, it continues to send heartbeat packets out to the inline security tool so that once the tool is back on-line, it will begin returning the heartbeat packets back to the TAP indicating that the tool is ready to go back to work. The TAP will then direct the network traffic back through the inline security tool along with the heartbeat packets placing the tool back inline.

Some of you may have noticed a flaw in the logic behind this solution!  You say, “What if the TAP should fail because it is also in-line? Then the link will also fail!” The TAP would now be considered a point of failure. That is a good catch – but in our blog on Bypass vs. Failsafe, I explained that if a TAP were to fail or lose power, it must provide failsafe protection to the link it is attached to. So our network TAP will go into Failsafe mode keeping the link flowing.

Glossary

  1. Single point of failure: a risk to an IT network if one part of the system brings down a larger part of the entire system.

  2. Heartbeat packet: a soft detection technology that monitors the health of inline appliances. Read the heartbeat packet blog here.

  3. Critical link: the connection between two or more network devices or appliances that if the connection fails then the network is disrupted.

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