Brad Christian

Brad Christian

Senior Search Engine Optimization Specialist

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Understanding Cyber Attack Signatures

In cybersecurity, an attack signature is a unique and recognizable characteristic or pattern that can help identify a specific cyberattack or malicious activity. One can think of this as a "calling card" of sorts, leaving behind clear evidence of who is behind an attack or what type of attack it is. This makes signature-based detection possible, increasing efficiency in detecting, tracing, and removing threats.

Attack signatures work when security systems keep a database of known threat behaviors. As traffic flows through the system, it is compared against this database to look for matches between the raw traffic data and the known attack signatures.

Some examples of attack signatures include:

  • Specific strings or patterns in code that identify types or families of malware.
  • Suspicious SQL commands or keywords that are commonly used in SQL injection attacks.
  • Irregular traffic patterns or packet headers can indicate a DDoS attack is underway.
  • Repeated login failures or failed authentication requests can be a sign a brute force attack is being attempted.

Recognizing attack signatures is vital to a strong security stance. Doing so allows cybersecurity professionals to leverage automated systems to enhance and expedite incident response. This improves overall defenses, protecting critical data and infrastructure.

Identifying Attack Signatures

Multiple layers of intelligence are needed to consistently identify attack signatures. Threats must first be identified, researched, and analyzed to discover the unique patterns they display during their nefarious activities. This requires detailed threat analytics to obtain this intelligence, helping security teams automate mitigations against known threats.

Once the threats have been analyzed and patterns are discovered, the signature must be generated. This involves creating the signature and defining its properties. These properties include:

  • Name or ID: Unique identifier for the signature.
  • Signature Type: Denotes whether the signature applies to responses or requests.
  • Attack Type: Defines the type of attack the signature defends against (e.g. DDoS, SQL injection, malware, etc.).
  • Risk: Portrays the potential damage the attack may cause.
  • Rule: The core of the signature where the content or patterns to look for are specified.

Now that the signatures are generated, they must be incorporated into security systems to be utilized. Signature databases can be connected to cybersecurity solutions to leverage threat intelligence feeds, allowing tools to utilize defined attack signatures automatically to improve defenses. Once the signatures are connected, security systems can scan for matches, alerting teams of positives for investigation and response.

Attack signatures and their databases should be continuously updated as threats are not static; threats adapt to defenses, so defenses must evolve to stay ahead of adversaries. In this process, a staging step is key to ensure attack signatures are blocked properly and do not create too many false positives.

Applications of Attack Signatures

As a crucial component of cybersecurity defenses, attack signatures have several practical applications that define different types of signatures. some examples include:

  • Antivirus Software: Automated detection of malware and other types of virus is enabled by scanning for known attack signatures. This signature-based detection can detect known malware downloaded by a user to automatically quarantine or delete it the infected file(s).
  • Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS): Known attack signatures can stop attacks before they gain a foothold with IDS and IPS solutions. For example, if a known SQL injection signature is found in network packet data, then the IDS or IPS can find or stop the threat.
  • Security Information and Event Management (SIEM) Systems: Correlation of events and identification of patterns to improve defenses is expedited or automated with an attack signature database connected to the SIEM. This improves response, aids investigation, and expedites response.
  • Web Application Firewalls (WAFs): Common web based attacks, like SQL injection or cross-site scripting (XSS), can be automatically identified and blocked by a WAF if the corresponding attack signatures are in the database.
  • Threat Intelligence Platforms or Feeds: Sharing threat information helps improve the security stance of the connected world. Leveraging known threat intelligence, such as attack signatures, across companies can help organizations stay ahead of evolving threats.

Signature-based detection has some shortcomings and limitations that need to be addressed, as it is not a perfect solution for cyber defense. Attack signatures do not exist for zero-day threats as there is little to no detail known about these novel attacks, leading to a lack of known signatures to block. They also need to be continuously updated as they are constantly evolving. Attackers may even modify their code to evade these defenses if they discover their signatures have been discovered.

How NETSCOUT Helps

ATLAS Intelligence Feed (AIF) is a curated threat intelligence system that feeds into many of NETSCOUT's DDoS protection products. This helps automatically block known DDoS threats from launching successful attacks and improving network, application, and service availability. NETSCOUT also has Omnis Cyber Intelligence with Adaptive Threat Analytics which leverages Threat intelligence feeds such as ATLAS or any third-party feeds via STIX/TAXII for known attack signatures and other threat details to improve the time between detection and response with swift, thorough investigation.