`Case 3:17-cv-05659-WHA Document 88-17 Filed 05/18/18 Page 1 of 4
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`EXHIBIT 19
`EXHIBIT 19
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`Case 3:17-cv-05659-WHA Document 88-17 Filed 05/18/18 Page 2 of 4
`Sky Advanced Threat Prevention
`>
`Sky Advanced Threat Prevention Administration Guide
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`TechLibrary >
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`How is Malware Analyzed and Detected?
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`Sky ATP uses a pipeline approach to analyzing and detecting malware. If an analysis reveals that the file is absolutely
`malware, it is not necessary to continue the pipeline to further examine the malware. See Figure 1.
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`Figure 1: Example Sky ATP Pipeline Approach for Analyzing Malware
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`Each analysis technique creates a verdict number, which is combined to create a final verdict number between 1 and
`10. A verdict number is a score or threat level. The higher the number, the higher the malware threat. The SRX Series
`device compares this verdict number to the policy settings and either permits or denies the session. If the session is
`denied, a reset packet is sent to the client and the packets are dropped from the server.
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`Cache Lookup
`When a file is analyzed, a file hash is generated, and the results of the analysis are stored in a database. When a file is
`uploaded to the Sky ATP cloud, the first step is to check whether this file has been looked at before. If it has, the
`stored verdict is returned to the SRX Series device and there is no need to re-analyze the file. In addition to files
`scanned by Sky ATP, information about common malware files is also stored to provide faster response.
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`Cache lookup is performed in real time. All other techniques are done offline. This means that if the cache lookup
`does not return a verdict, the file is sent to the client system while the Sky ATP cloud continues to examine the file
`using the remaining pipeline techniques. If a later analysis returns a malware verdict, then the file and host are
`flagged.
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`Antivirus Scan
`The advantage of antivirus software is its protection against a large number of potential threats, such as viruses,
`trojans, worms, spyware, and rootkits. The disadvantage of antivirus software is that it is always behind the malware.
`The virus comes first and the patch to the virus comes second. Antivirus is better at defending familiar threats and
`known malware than zero-day threats.
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`Sky ATP utilizes multiple antivirus software packages, not just one, to analyze a file. The results are then fed into the
`machine learning algorithm to overcome false positives and false negatives.
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`Static Analysis
`Static analysis examines files without actually running them. Basic static analysis is straightforward and fast,
`typically around 30 seconds. The following are examples of areas static analysis inspects:
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`Metadata information—Name of the file, the vendor or creator of this file, and the original data the file was compiled on.
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`Categories of instructions used—Is the file modifying the Windows registry? Is it touching disk I/O APIs?.
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`Case 3:17-cv-05659-WHA Document 88-17 Filed 05/18/18 Page 3 of 4
`File entropy—How random is the file? A common technique for malware is to encrypt portions of the code and then decrypt it
`during runtime. A lot of encryption is a strong indication a this file is malware.
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`The output of the static analysis is fed into the machine learning algorithm to improve the verdict accuracy.
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`Dynamic Analysis
`The majority of the time spent inspecting a file is in dynamic analysis. With dynamic analysis, often called
`sandboxing, a file is studied as it is executed in a secure environment. During this analysis, an operating system
`environment is set up, typically in a virtual machine, and tools are started to monitor all activity. The file is uploaded
`to this environment and is allowed to run for several minutes. Once the allotted time has passed, the record of activity
`is downloaded and passed to the machine learning algorithm to generate a verdict.
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`Sophisticated malware can detect a sandbox environment due to its lack of human interaction, such as mouse
`movement. Sky ATP uses a number of deception techniques to trick the malware into determining this is a real user
`environment. For example, Sky ATP can:
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`Generate a realistic pattern of user interaction such as mouse movement, simulating keystrokes, and installing and launching
`common software packages.
`Create fake high-value targets in the client, such as stored credentials, user files, and a realistic network with Internet access.
`Create vulnerable areas in the operating system.
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`Deception techniques by themselves greatly boost the detection rate while reducing false positives. They also boosts
`the detection rate of the sandbox the file is running in because they get the malware to perform more activity. The
`more the file runs the more data is obtained to detect whether it is malware.
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`Machine Learning Algorithm
`Sky ATP uses its own proprietary implementation of machine learning to assist in analysis. Machine learning
`recognizes patterns and correlates information for improved file analysis. The machine learning algorithm is
`programmed with features from thousands of malware samples and thousands of goodware samples. It learns what
`malware looks like, and is regularly re-programmed to get smarter as threats evolve.
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`Threat Levels
`Sky ATP assigns a number between 0-10 to indicate the threat level of files scanned for malware and the threat level
`for infected hosts. See Table 1.
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`Table 1: Threat Level Definitions
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`Threat Level
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`Definition
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`0
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`1 - 3
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`4 - 6
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`7 -10
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`Clean; no action is required.
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`Low threat level.
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`Medium threat level.
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`High threat level.
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`For more information on threat levels, see the Sky ATP Web UI online help.
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`Modified: 2017-06-07
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`Case 3:17-cv-05659-WHA Document 88-17 Filed 05/18/18 Page 4 of 4
`Case 3:17-cv-05659-WHA Document 88-17 Filed 05/18/18 Page 4 of 4
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