Category Archives: Info Security

2020
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Digital Forensics, Info Security, Security Blogs, Threat Hunt

How to Quickly Analyze a PCAP File

 I am so excited to introduce NFPA – a Network Forensic Processing & Analysis tool! 

network_security_ediscovery_network_analysis_network_monitor_forensics_tools_pcap_forensics_packet_forensics_capture_wireshark
NFPA – Network Forensic Processing & Analysis

My purpose behind NFPA tool is to provide Cybersecurity analysts a more efficient and automated (“click & forget”) means of executing commonly-used, open-source network forensics utilities and analysis queries against a piece of network evidence (PCAP).

NFPA tool helps optimize investigations by reducing errors that are typically involved in manually processing and analyzing network-based evidence through various popular tools and command-line options. 

Using NFPA, an analyst can:

  1. quickly process case evidence through various popular tools and utilities all by a simple script execution
  2. review results from 60+ individual, multi-purpose queries pre-ran again the evidence
  3. view the native output from all of the evidence process utilities – providing the opportunity for any validation or further analysis

All of the above is organized in an easy-to-understand structure which allows the analyst to quickly find answers as well as the authoritative source of those answers. 

Here is a quick demo of NFPA in action:

A key requirement when designing NFPA was to keep dependencies as minimum as possible. I wanted to make sure I leverage a platform that is already commonly used by analysts which is pre-configured with all of the necessary tools and capabilities. This would allow analysts to instantly begin their work on investigations and not have to deal with the underlying system engineering.

To that end, here is the only dependency:

Additionally, the NFPA is built-in Bash. Which means you do not have to import any specific libraries or run a certain version. Another advantage of using Bash is that you will most likely be able to run NFPA on other Linux distributions (may need to install some purpose-built network forensic tools separately).

The first version of the tool is now available on Github. Please check it out and let me know what you think!

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2020
Leave a comment
Digital Forensics, Info Security, Security Blogs, Threat Hunt

What your CMD command line security is missing

Here is what your should do to increase your cmd command line security
Gap in Your Command-line Security

I want to write a follow-up on my last post about chain-of-commands not properly being captured by many defensive tools. During further research and testing, I observed that built-in Windows Command line actions are also not captured.

For instance, a simple act of deleting a file from the CMD Command-line is neither captured in SYSMON or in Windows Event logs:

 CMD.EXE > del /f test_file.txt
file_del_cmd

The only event observed in SYSMON for the above action was the following:

del_file

Additionally, nothing notable was observed in Windows Event logs.

This simple act of deleting a file is a common technique used by the adversaries. This action could be done both manually or through malware. One example where this technique is used is in the case of the Robbinhood Ransomware. In this sandbox report, you can see various quite-delete operations that Robbinhood malware executes.

I understand that there are other means of extracting CMD Command-line execution content. However, many of those require digital forensics analysis.

For instance, you can review Command-line history by analyzing the memory capture using a tool such as Volatility with plugins: cmdscan, consoles or just running strings against the memory image. However, this type of analysis requires either a memory image capture or a specialized commercial solution that can scan live memory content (example). Unfortunately, most organizations do not have access to these enterprise-solutions thus their ability to hunt for such Command-line techniques becomes limited.

MITRE ATT&CK Evaluations also has an entry for this technique 9.C.4 File Deletion where you can select various technologies from the drop-down list and see how they detect this technique.

If you are collecting and hunting full CMD Commandline, I would love to hear about your feedback; especially, if the technology/method that you are using is not one of the ones tested in ATT&CK Evaluations above.

https://attackevals.mitre.org/technique_comparison.html?round=APT29&step_tid=9.C.4_T1107&vendors=

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2020
Leave a comment
Digital Forensics, Info Security, Investigation, Security Blogs

Who Else is Blind to Chain-of-Commands | Adversary Technique

photo-1567635102602-73000b63761a

I recently came across a technique that potentially allows the adversary to both execute and evade detection that is simple to execute, however, to my surprise, not entirely captured by detection tools (at least not by those that I have tested).

In this quick post, I will share my findings & analysis and I am interested in any feedback around options for detection.

Technique Description: The adversary executes a custom-developed, chain-of-commands that they execute together as a single command-line using Windows CMD.EXE. This execution could be achieved through malware or the adversary could manually perform it on a system under their control.

One of the key advantages of this technique for the adversary is that, as of this writing, SYSMON (10.0.4.2), and maybe even some commercial EDR solutions, do not capture such chain-of-commands as a single execution. Instead, these tools typically log this activity separately. I found nothing in the SYSMON logs or Windows native event logs that indicate that multiple commands were executed together as part of a chain.

If what I have observed in true, then I think this lack of total context makes it difficult for incident responders, threat hunters, or security monitoring professionals to identify such activity as anomalous among a large number of events. On the other hand, it allows the adversary to hide in plain sight.

Technique Use in Real Malware: One particular malware where I found this technique being used was in the RobbinHood Ransomware. In my analysis of these two samples (1, 2), this chain-of-command technique can be observed in a couple different ways. However, in one specific instance, RobbinHood uses this technique to check for network connectivity, terminates its previously-launched malicious process and subsequently deletes that same process executable quietly from the system permanently. The command itself was as follows:

ping 1.1.1.1 -n 1 -w 3000 > 
& taskkill /f /im steel.exe & Del /f /q ‘C:\Users\user\Desktop\steel.exe’

Atomic Test: To simulate the above technique, I developed this benign chain-of-commands, which essentially, first checks network connectivity by making a single ICMP ping request to a Google’s public DNS address, and then it terminates a running Chrome web browser process.

ping 8.8.8.8 -n 1 -w 3000 > Nul & taskkill /f /im chrome.exe

chain_of_command_atomic_test

Here is what I observed in SYSMON on the atomic test above:

First, you see an entry for PING.EXE portion of the chain-of-command:

ping_sysmon

Second, you see separate entry for the latter portion of the chain where the CHROME.EXE process is terminated:

taskkill_sysmon

It is evident in the SYSMON events above that both processes share the same Parent Process ID. However, while both events share the same ParentProcessID of 12120, there isn’t any explicit indication that these commands were executed together as part of a chain-of-commands. Which I believe is an important context that is missing as it would not only stick-out during Incident Response/Hunt/Monitoring; especially if the system under investigation and has no business purpose to running such chain-of-commands.

I do want to highlight that I think SYSMON is capturing what it is supposed to capture – a process creation. It captured as each process was created on the system; which was separately one at a time. The limitation appears to be at the operating system level where this data is not captured.

I look forward to feedback and how are you detecting this technique in your environments!

Reference:

MalwareReference
Trojan; possibly Big Bang APT1. https://bit.ly/2xaAVNr
2. https://bit.ly/2KBddgp
3. https://bit.ly/3cUVkFH
Raccoon Stealerhttps://bit.ly/35i8dXP
InstallCube Trojanhttps://bit.ly/2yMjmDI
GreenKit Bitcoin Mining Rootkithttps://bit.ly/3aDRI9i
TROJ_VICEPASS.A1. https://bit.ly/2y2PrHr
2. https://bit.ly/2xem5Wm
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2019
Guide, Info Security, Original, Review, Security Blogs, Technology

Free web application vulnerability software

The goal of this post is to provide an overview of an awesome OWASP project which is designed to find vulnerabilities in web applications called: Zed Attack Proxy (ZAP). I have known about ZAP for a while but I just thought I do a quick write up.

ZAP was selected as the second top security tool of 2014 by ToolsWatch.org. The project is extremely well documented with a user guide, FAQs, tutorials, etc., all conveniently located on its wiki. Also, since there is already so much professional documentation available for this project, this post will not pay too much attention to its features and functionality, but rather on my experience with the tool and how I got it up and running.

ZAP can run on Windows, Linux, and OS/X, and it can be downloaded from here. I downloaded ZAP on my Ubuntu 13 Desktop instance. Note that Java version 7 is required for both Windows and Linux. Also, ZAP comes included in several security distributions — a list can be found here.

After you have extracted the ZAP_2.3.1_Linux.tar.gz, you just need to run the zap.sh:

web_app_pentesting

Soon after that, the application will auto-start. You may be prompted to generate an SSL certificate — which you will need in order to test secure applications — however, I skipped that initially since you can always come back to it.

The last step in the installation process is similar to BURP and that is to configure your browser to use ZAP as a proxy. The ZAP team has a nice guide here on how to do this for the most common browsers. I set Firefox with ZAP proxy:

owasp_zap_tutorial

After completing the step above, you are done with the installation process and are ready to kick off a scan. Here is how the home page should look like.

pentesting_tool

The first thing I would like to call your attention to before setting up a scan is to please make sure you have explicit permission before you scan any site. It is best to deploy a dummy web application on your local machine and use that to scan and learn.

If you have questions about where to start in ZAP, the perfect place to start would be the awesome user guide that comes with the installation. It can be accessed from Help > OWASP ZAP User Guide:

free vulnerability scanner

I believe everything that is found on ZAP’s online wiki can be located in this user guide, if not more. I think that is great because as you look through the home page and menu options, it can be a bit overwhelming. But you can find answers to what all of the buttons do from the user guide as well as from here and here.

Going back to the homepage, you will see the following option:

best web vulnerability scanner

This is probably the best place to start off with your first scan. Alternatively, you could visit your demo site using the browser on which you configured ZAP proxy, and as you navigate through the site, ZAP will begin to populate the structure on the left home-page panel:

SitesAfter you have the site structure similar to the above, you can take your test in several different directions — most of which can be viewed by simply right-clicking on any of the site’s pages:

website vulnerability scanner kali

If you are fairly new to web application security (like I am) chances are that whichever direction you choose to take, you will have questions. Fortunately, there are YouTube videos that you can refer to here. One video in particular that you should check out is this as it can come in handy when you want ZAP to auto-authenticate to your site’s login fields.

This concludes the introduction of a feature-packed tool from a long list of tools that I plan to explore. This already looks to be the best of the bunch. Even if you just heard of web application security, and you are looking to try one, this is a must-have for you; and it’s free! I am really glad that I got the chance to play with this tool and now it is part of my toolkit.  I recommend that you check it out to begin rockin’ on your Web Application Security game!

Follow me on Twitter: @azeemnow 

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