The six step incident handling process is appropriate for all forms of incidents, including Advanced

Persistent Threat (APT) style attackers.  The APT is characteristically well funded teams of workers who

are tasked with ex-filtrating intellectual property from targeted organizations.  The data sought is typically

insufficiently defended relative to its value, creating a situation where funding the theft of the data is

economically advantageous compared to developing the data from scratch.  At times, however, the

adversary’s intent is to diminish the value of the data to the rightful owner.  Denial of service reduces the

availability of the data.  Potentially more damaging would be manipulating the integrity of the data such

that the data owner acts in error based on the tampered data.

 

While the Incident Handling process is adaptable to respond to APT style attacks, and some actions should

be taken for any incident regardless of the threat involved, there are response strategies that are better

suited to an APT compromise.  The following outline is intended to be a checklist of actions appropriate to

dealing with the threat and a compromise accomplished by this threat.  Customized tailoring to each

environment and situation is warranted and recommended.  But this guide is a generalized set of actions

appropriate to APT response.

  1. Preparation
    1. Identify ownership and responsibility for all systems (including data) in the enterprise
    2. Clear communication channels
      1. Capabilities for encrypted email communication (potentially not using primary email server)
      2. Capabilities for encrypted chat messaging (potentially not using primary chat server)
      3. Telephone call list for coordination stored offline
      4. Understanding which parties are to be notified
        1. Develop contact list per system
          1. System Owner
            1. Possibly designated Point of Contact (POC), too
          2. Technical POCs
            1. Possible after hours / rotation / call list for response

 

  1. Incident Response aware of and capable to address APT style attacks
    1. Clear understanding of this threat’s characteristics
      1. Management has clear understanding of the threat
    2. Authorized to respond on all systems in enterprise
    3. Funded to perform extended investigations
      1. If Incident handling isn’t currently 24×7, what resources are available to continue IR work throughout sustained response

 

  1. In house capability or contracts with business partner for
    1. Incident Response
    2. Forensic Investigation
    3. Malware Reverse engineering

 

  1. Containment Strategy for APT
    1. Two basic strategies:
      1. Watch and Learn
      2. Disconnect
    2. Define the Standard Operating Procedures (SOP) for when each scenario is used
    3. Define a methodology for an incident responder to deviate from SOP as needed
      1. This methodology should be part of SOP
        1. Include steps for notification and justification of planned deviation

 

  1. Press Team

 

  1. Legal Team

 

  1. Identification
    1. Remote Access Trojan (RAT)
    2. Command and Control (C+C)
    3. Encrypted Communications discovered
    4. Covert Channel discovered
    5. Host based IDS/IPS alert of unexpected system call, data access, port open
    6. Direct External Notification (Law Enforcement, Business Partner)
    7. Indirect External Notification (Open Source Intelligence of behavior, search in your environment)
    8. Data discovered outside of organization (pastebin, news)
    9. Blackmail “offer”
    10. Notification to internal staff must occur in a discrete fashion
      1. Encrypted
      2. Limited to only those with need to know
      3. Authorization to add additional resources to response effort is limited to Incident Response Management, and/or Business Unit Management
      4. Categorize known Severity and Impact
      5. Provide updates as important new information comes to light

 

  1. Containment
    1. Watch and Learn versus Disconnect
      1. Have this plan in place in advance! (per Preparation phase)
    2. Extract and identify characteristics of adversary
      1. Identify other affected systems
      2. Utilize updated Network Intrusion Detection System (NIDS) / Network Intrusion Prevention System (NIPS) / Host Intrusion Detection System HIDS / Host Intrusion Prevention System (HIPS) signatures to assess assets throughout
        1. Update NIDS/NIPS/HIDS/HIPS to search for characteristic:
          1. Files
          2. System calls
          3. Processes
          4. Network
            1. Ports
            2. IP addresses
            3. Host names
          5. Use Packet Capture (pcap) / network forensic devices to replay old traffic to identify additional infected systems
        2. Identify what has been stolen
          1. Full pcap (which retains a copy of all data from the wire) is invaluable in this regard
            1. Even w/ full pcap, traffic may be encrypted
            2. Must break encryption to fully assess damage
            3. May need host based forensics in coordination with full pcap to complete this assessment
          2. Intellectual Property
          3. Resources
            1. Bandwidth

 

  1. Identify legal ramifications
    1. PCI
    2. HIPAA
    3. California HR (SB 1386) notification requirements
    4. European data breach requirements
    5. Many possible other legal ramifications

 

  1. Is it appropriate to remove entire segment from network (disconnect?)
    1. May be easier to identify malicious network traffic if the environment is still online because the traffic is still flowing, but may have ongoing loss of data

 

  1. Contact Law Enforcement (LE)?
    1. FBI typically interested in this sort of attack
    2. The decision to involve LE may affect the amount of and degree of public reporting

 

  1. Public Reporting?
    1. US-CERT
    2. Industry requirements?
      1. Defense Industrial Base (DIB)
      2. Medical
      3. Sarbanes-Oxley (SOX) / Gramm-Leach-Bliley (GLB)
    3. Partner notification
    4. Customer Notification

 

  1. Eradication
    1. Imperative that all affected systems be collected, and full forensic images be
      1. Memory Images very important for APT since some techniques do not write to hard drive
        1. Also may assist in assessment of ex-filtrated data
          1. If data ex-filtration uses symmetric cipher, then decryption key will be present in Random Access Memory (RAM)
        2. Preferred method is to seize hard drives as evidence, replace those hard drives with new system
          1. Preferred because this drive is the legal evidence of wrongdoing
          2. Any pcap / network information that could be evidence must also be preserved
            1. Have SOP showing handling of evidence for pcap
            2. Associate with case, make MD5 and SHA256 hash of stored pcap
          3. Secondary option is to make forensic image (for example, remotely via encase enterprise or another enterprise forensic solution, then wipe drives and re-image
          4. Without this evidence, a thorough investigation cannot be completed

 

  1. Close all network vectors of ex-filtration
    1. HTTPS inspection via proxy and Secure Socket Layer (SSL) intercept
    2. Prohibit outbound encrypted communication except for known, authorized peers
    3. Techniques demonstrated during this APT incursion
  2. Close all vectors of re-infection
  3. Remove all RAT / C+C / Backdoors

 

  1. Recovery
    1. Close future network vectors of ex-filtration
      1. HTTPS inspection via proxy and SSL intercept
      2. Prohibit outbound encrypted communication except for known, authorized peers
    2. Re-engineer systems to prevent reinfection
    3. Segment critical data to more restricted areas
    4. Implement auditing for critical data access
    5. Identify individuals within environment who purposefully or accidentally aided APT, for counseling / training / discipline

 

  1. Lessons Learned
    1. Assess Executive posture toward Incident Handling and Information Is this loss just a cost of doing business, or is it an opportunity for massive change?
    2. Develop Intelligence group for identification of APT attacks
      1. Characterize the adversary
        1. Use “Kill Chain” model or other counter-intelligence strategies
        2. Adversary has limited resources, as Will re-use assets.
        3. Attribution is very difficult, but is the end goal for counter-intelligence
      2. Campaign to assist business members of various sorts of threats
        1. Malware drive by download = smash and grab from car
        2. APT = home invasion / hostage situation
        3. Explain potential loss of long term competitive advantage of business due to loss of IP
      3. Re-catalog and re-value assets in light of APT strategies and targets
        1. Avoid Blame, use incident to enhance capabilities
      4. Enhance methods for APT response, including
        1. “Watch and learn” capabilities
        2. Honey tokens for Intellectual Property (IP)
        3. Active honey-nets
        4. Deception capabilities
      5. Aggregation of data from all sources
        1. Security Information and Event Management (SIEM) if possible
        2. Identify additional data sources
          1. Firewalls
          2. HIDS
          3. Windows Active Directory (AD) / Lightweight Directory Access Protocol (LDAP) / Authentication
          4. Wireless infrastructure
          5. Any system not currently providing data
            1. Servers
              1. Web servers
              2. Data base servers
            2. Workstations
  • Mobile devices
APT SANS

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