Archive | 2015
System Files Typical File Size Detection with YARA

YARA Rules to Detect Uncommon System File Sizes

YARA is an awesome tool especially for incident responders and forensic investigators. In my scanners I use YARA for anomaly detection on files. I already created some articles on „Detecting System File Anomalies with YARA“ which focus on the expected contents of system files but today I would like to focus on the size of […]

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Endpoint Attacker Detection

Synergetic Effects of Network and Host Based APT Detection

People often ask me if they still need our host based scanner THOR now that they have bought a network appliance that already checks all content that goes into and leaves their network. I normally answer that it is not a question of one solution versus another, but a combination of solutions to achieve the […]

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Yara Signatures

How to Write Simple but Sound Yara Rules – Part 2

Months ago I wrote a blog article on „How to write simple but sound Yara rules„. Since then the mentioned techniques and tools have improved. I’d like to give you a brief update on certain Yara features that I frequently use and tools that I use to generate and test my rules. (mehr …)

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Threat Intel CSV Lookup in Splunk

Splunk Threat Intel IOC Integration via Lookups

Today most security teams have access to a lot of different information sources. On the one hand they collect log data from different sources and try to correlate them in a useful way in so-called SIEM systems. On the other hand they receive threat information from different sources like APT reports, public or private feeds […]

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Detect System File Manipulations with SysInternals Sysmon

SysInternals Sysmon is a powerful tool especially when it comes to anomaly detection. I recently developed a method to detect system file manipulations, which I would like to share with you. We know how to track processes with the standard Windows audit policy option „Audit process tracking“, but Sysmon messages contain much more information to […]

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APT Detection is About Metadata

People often ask me, why we changed the name of our scanner from „IOC“ to „APT“ scanner and if we did that only for marketing reasons. But don’t worry, this blog post is just as little a sales pitch as it is an attempt to create a new product class. I’ll show you why APT […]

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Yara signature definition

How to Write Simple but Sound Yara Rules

During the last 2 years I wrote approximately 2000 Yara rules based on samples found during our incident response investigations. A lot of security professionals noticed that Yara provides an easy and effective way to write custom rules based on strings or byte sequences found in their samples and allows them as end user to […]

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Sysmon Example Config XML

Sysmon is a powerful monitoring tool for Windows systems. Is is not possible to unleash all its power without using the configuration XML, which allows you to include or exclude certain event types or events generated by a certain process. Use the configuration to exclude high volume sources or event types of less interest (e.g. […]

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