TLS Handshake Anomaly Detection for Malicious Software Identification

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing network security measures struggle to detect malicious software effectively, as it often avoids detection by abandoning TLS/SSL connection handshakes when a proxy is detected, making it difficult to differentiate between legitimate and malicious traffic.

Innovation Solution

Monitoring and analyzing unusual TLS/SSL handshake behavior, such as abandoned handshakes, to identify potential malicious software by processing telemetry and historical data, and applying techniques to determine if the behavior is indicative of malicious activity, which may involve flagging or quarantining affected endpoints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If TLS/SSL interception proxies are used to detect malicious traffic, then encrypted traffic can be monitored, but malicious software can detect the proxy and abandon handshakes to avoid detection

Engineering Contradiction:
Improvedetection accuracyVSAvoidmalicious software evasion
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful evasion behavior (abandoned handshakes) into a beneficial detection signal. By monitoring and analyzing handshake abandonment patterns, the system identifies malicious software that attempts to evade detection through proxy abandonment, thereby turning the evasion tactic into a detection opportunity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The system implements feedback by continuously monitoring handshake behavior and using the observed patterns to improve detection accuracy. The analysis of telemetry data and historical information creates a feedback loop that refines the ability to distinguish between legitimate proxy abandonment and malicious evasion attempts.

Inventive Principle:
Principle #23Feedback

2Reliability

If malicious software communicates with C&C servers using encrypted traffic, then communication security is maintained, but detection of malicious activity becomes difficult

Engineering Contradiction:
Improvesecurity detection capabilityVSAvoidencrypted traffic visibility
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts specific handshake information (telemetry data) from the encrypted TLS/SSL traffic without requiring decryption of the full communication. By focusing on the handshake phase metadata rather than the encrypted payload, the system gains detection capability while maintaining traffic encryption.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system changes the detection parameter from analyzing encrypted content to analyzing handshake metadata parameters. By monitoring handshake abandonment patterns, connection timing, and telemetry data rather than attempting to decrypt traffic, the system achieves detection of malicious activity without losing the benefit of encrypted communication.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If handshake behavior is monitored to identify malicious software, then detection accuracy improves, but false positives may increase

Engineering Contradiction:
Improvemalicious software identification accuracyVSAvoidfalse positive rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system performs preliminary analysis of handshake behavior patterns before making definitive malicious software identification. By establishing baselines of normal handshake behavior and comparing observed patterns against these baselines, the system reduces false positives while maintaining detection accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces historical information and telemetry data as intermediary evidence between raw handshake observations and malicious software identification. This intermediary analysis layer provides context and corroboration, reducing the likelihood of false positives by requiring multiple indicators before confirming malicious activity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS9854000B2Method and apparatus for detecting malicious software using handshake information
Publication Date: 2017.12.26 CISCO TECHNOLOGY INC
  • US9854000B2 patent drawing
  • US9854000B2 patent drawing
  • US9854000B2 patent drawing

AI summary

In one embodiment, a method includes identifying unusual behavior with respect to a handshake between a first endpoint and a second endpoint that are included in a network, and determining whether the unusual behavior with respect to the handshake indicates presence of malicious software. The method also includes identifying at least one of the first endpoint and the second endpoint as potentially being infected by the malicious software if it is determined that the unusual behavior with respect to the handshake indicates the presence of malicious software.