Inflated Files for Network Exfiltration Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current anomaly detection tools in network security suffer from high false-positive alert rates, making it difficult for administrators to detect data exfiltration attempts effectively, as malicious actors can evade detection by encrypting data, randomizing malware, or spreading exfiltration over time and multiple targets.

Innovation Solution

The system employs an iteratively updated network traffic model to create 'inflated files' with arbitrary or random data, making exfiltration attempts more conspicuous by triggering anomaly detection alerts, while minimizing false positives through continuous monitoring and proactive file modification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If anomaly detection tools are used to detect data exfiltration attempts, then detection capability is improved, but false-positive alert rates increase

Engineering Contradiction:
Improvedetection capabilityVSAvoidfalse-positive alert rates
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system proactively creates inflated files with sensitive data indicators before any exfiltration attempt occurs. These pre-prepared files are strategically placed in the network environment to serve as traps. When malicious actors attempt to exfiltrate what they believe is sensitive data, they actually download these inflated files, triggering anomaly detection alerts with high confidence that genuine exfiltration is occurring, thereby reducing false positives.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The inflated files act as an intermediary between the actual sensitive data and the anomaly detection system. Instead of directly monitoring for exfiltration of real sensitive data (which is difficult to detect), the system uses these decoy files as mediators that clearly mark exfiltration attempts when downloaded, providing a reliable signal to the detection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If exfiltration detection methods watch for sensitive terms or known sensitive data, then detection accuracy is improved, but malicious actors can circumvent detection by encrypting data

Engineering Contradiction:
Improvedetection accuracyVSAvoidcircumvention capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system creates copies of sensitive data files and inflates them with arbitrary data to create decoy files. These copies contain the same sensitive data indicators (such as file headers, metadata, or content signatures) that would be present in real sensitive files, but they are substantially larger due to the added inflation data. This allows the detection system to monitor for these indicators without needing to decrypt or analyze the actual sensitive data content.

Inventive Principle:
Principle #26Copying

3Reliability

If exfiltration detection methods aggressively monitor transfer channels, then detection capability is improved, but malicious actors can circumvent by moving to other channels

Engineering Contradiction:
Improvedetection capabilityVSAvoidchannel switching capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system proactively places inflated files across multiple network locations and channels before exfiltration attempts occur. By having these decoy files预先 distributed throughout the network infrastructure, the system ensures that regardless of which channel or protocol malicious actors use for exfiltration, they are likely to encounter and download an inflated file, triggering detection.

Inventive Principle:
Principle #10Preliminary action

4Device complexity

If anomaly detection looks for traffic spikes at certain times or specific hosts, then detection simplicity is improved, but malicious actors can circumvent by spreading exfiltration over extended periods and multiple targets

Engineering Contradiction:
Improvedetection simplicityVSAvoiddetection effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system divides the network into multiple segments and places inflated files at various locations across different hosts, departments, and network zones. This segmentation approach transforms the detection problem from monitoring entire network traffic patterns to monitoring individual file downloads at specific locations, simplifying the detection mechanism while maintaining comprehensive coverage against distributed exfiltration attempts.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS10924502B2Network security using inflated files for anomaly detection
Publication Date: 2021.02.16 NOBLIS INC
  • US10924502B2 patent drawing
  • US10924502B2 patent drawing
  • US10924502B2 patent drawing

AI summary

Techniques for providing network security and anomaly detection are disclosed. In some embodiments, network traffic may be monitored in order to create a model of network traffic over a first period of time. Based on the model of network traffic, one or more inflated files may be created and stored on a system, wherein the inflated files are of a sufficient file size such that attempts to exfiltrate one or more of the files may be detected based by network monitoring tools. The inflated files may further include one or more indicators of sensitivity, including indicators of the presence of sensitive information that is not actually included in the inflated files. Network traffic characteristics may then be repeatedly or continuously monitored in order to update the size of the one or more inflated files based on changes in network traffic characteristics.