Investigating Teams Logs

Published 28/04/2023 / by jeff / Leave a Comment
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Microsoft Teams logs contain information about various user activities within the Teams platform, such as messaging, meetings, calls, and other interactions. These logs can be accessed through the Microsoft 365 Compliance Center’s Audit log search or by using the Office 365 Management Activity API.

Here’s a list of some important fields available in Microsoft Teams logs, along with a brief description of what they represent:

  1. CreationTime: The date and time (UTC) when the event occurred.
  2. UserId: The ID of the user who performed the action.
  3. UserKey: The user key of the user who performed the action. It can be a user’s Azure AD ID or an external user’s email address.
  4. UserType: Indicates whether the user is internal or external to the organization.
  5. UserAgent: Information about the device, operating system, or client app used by the user who performed the action.
  6. Operation: The type of action performed by the user, such as “TeamCreated”, “ChannelDeleted”, “MeetingStart”, or “CallRecorded”.
  7. Workload: The Microsoft 365 service associated with the event. For Teams logs, this will be “MicrosoftTeams”.
  8. ResultStatus: The result of the action, such as “Succeeded” or “Failed”.
  9. ClientIP: The IP address of the user who performed the action.
  10. CorrelationId: The unique identifier for the event, which can be used to correlate multiple related events in the log.
  11. ObjectId: The ID of the object affected by the action, such as a team, channel, or message.
  12. TargetUserId: The ID of the user affected by the action, such as the recipient of a message or the user added to a team.
  13. TeamGuid: The unique identifier for the team associated with the event.
  14. ChannelGuid: The unique identifier for the channel associated with the event.
  15. MessageGuid: The unique identifier for the message associated with the event.
  16. MeetingGuid: The unique identifier for the meeting associated with the event.
  17. CallGuid: The unique identifier for the call associated with the event.
  18. ItemName: The name of the object affected by the action, such as a team or channel name.
  19. ItemType: The type of object affected by the action, such as “Team”, “Channel”, “Message”, “Meeting”, or “Call”.
  20. CustomProperties: Additional custom properties specific to the event, such as the meeting title, call duration, or message content.

These fields provide detailed information about the user activities within Microsoft Teams, allowing administrators and security professionals to monitor and analyse events for auditing, compliance, and security purposes.

Ransomware and Incident Response: Dealing with Cyber Threats

Published 24/04/2023 / by jeff / Leave a Comment
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Ransomware is a major threat to businesses, governments, and individuals. It is a type of malware that targets computer systems and encrypts the files on them. The attackers then demand payment, usually in the form of cryptocurrency, for the decryption keys. Ransomware attacks have become increasingly common, and they can have serious consequences if not addressed quickly and effectively. In this blog post, we will explore the dangers posed by ransomware and the importance of incident response in dealing with cyber threats.

What is Ransomware?

Ransomware is a type of malware that encrypts the files on a computer system and demands payment for the decryption keys. There are different types of ransomware, but they all work in a similar way: once the malware infects a system, it encrypts the files and displays a message on the victim’s screen, demanding payment in exchange for the decryption keys. In many cases, the attackers threaten to delete the files if the ransom is not paid.

Ransomware attacks can be devastating for organizations and individuals. They can cause major disruptions to business operations, resulting in financial losses and reputational damage. In some cases, they can also result in the loss of sensitive data, which can have legal and regulatory implications.

How Does Ransomware Spread?

Ransomware can spread in a variety of ways, including through phishing emails, malicious websites, and infected software. It often exploits vulnerabilities in outdated software or operating systems. Once ransomware infects a system, it can quickly spread to other connected devices or network resources.

Why Is Incident Response Important?

Incident response is the process of responding to cyber threats and minimizing their impact. It involves a coordinated effort between IT professionals, security teams, and other stakeholders to detect, contain, and mitigate the damage caused by a cyber attack.

An effective incident response plan is critical for dealing with ransomware attacks. It can help organizations minimize the impact of an attack and reduce the time it takes to recover from it. A good incident response plan should include the following steps:

1. Detection: The first step in incident response is detecting the attack. This can be done with the help of security tools, monitoring systems, and user reports.

2. Containment: Once an attack has been detected, the next step is to contain it. This involves isolating the infected systems or devices to prevent the attack from spreading further.

3. Investigation: After the attack has been contained, the next step is to investigate it. This involves identifying the type of ransomware, how it entered the system, and what files have been encrypted.

4. Recovery: Once the investigation is complete, the next step is to recover from the attack. This involves restoring the affected systems or devices from backups, decrypting files, and patching vulnerabilities that were exploited by the attackers.

5. Post-incident analysis: The final step is to conduct a post-incident analysis to identify areas for improvement in the incident response plan.

Conclusion

Ransomware is a serious threat to organizations and individuals. It can cause significant financial and reputational damage, as well as the loss of sensitive data. Incident response is critical for dealing with ransomware attacks and minimizing their impact.

To protect against ransomware, organizations should take a proactive approach to cybersecurity. This includes keeping software up-to-date, training employees on how to recognize phishing attacks, and implementing security measures such as firewalls and antivirus software.

In conclusion, ransomware attacks are here to stay, and the best defense is a good offense. By being prepared and having an effective incident response plan in place, organizations can reduce the risk of a successful attack and minimize its impact if one does occur.

Nokoyawa Ransomware

Published 11/04/2023 / by jeff / Leave a Comment
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In recent months, new ransomware has been discovered called Nokoyawa, which has become a considerable threat for businesses worldwide. Nokoyawa targets Windows operating systems and propagates through the network via remote execution protocols, which enables the ransomware to impact a large number of systems with minimal exposure.

Nokoyawa encrypts files on infected systems and appends filenames with “.nokoyawa” extension. It then creates a ransom note named “HOW_TO_RECOVER_YOUR_FILES.html” in all encrypted directories, with instructions on how to pay the ransom amount to get the decryption key. The ransom note also serves as proof of the successful encryption of files.

Nokoyawa has multiple communication channels with the command and control infrastructure. The malware sends information about the infected system to the remote server, receives instructions from the server, and sends back the necessary logs and user credentials back to the server. In this way, the ransomware makes it almost impossible to track down the attacker’s location.

To identify the presence of Nokoyawa ransomware, we have observed some indicators of compromise (IOCs) in the infected systems. The IOCs are as follows:

  • Network traffic to IP 103.205.134.171 on port 443
  • Network traffic to IP 45.145.95.244 on port 80
  • IOCs in PowerShell command-lines such as Base64-encoded strings, file paths, processes, and registry keys

Organizations can mitigate the risks of Nokoyawa by implementing proper security measures such as data backup and recovery systems, file and folder permission policies, email filters, and antivirus programs. Additionally, keeping systems and software up to date by applying security patches can also help to prevent the spread of Nokoyawa ransomware.

In conclusion, Nokoyawa ransomware is a significant threat to businesses and organizations. Recognizing the IOCs and applying preventive measures can help organizations safeguard against this malicious software. Maintaining updated security standards and being vigilant about suspicious network activity are essential components of a proactive security strategy.


https://securelist.com/nokoyawa-ransomware-attacks-with-windows-zero-day/109483/

Steps to respond to ransomware

Published 11/04/2023 / by jeff / Leave a Comment
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In the face of increasing ransomware attacks, it has become essential to understand the necessary steps to respond to such threats effectively. If you suspect ransomware on your system, it’s imperative to take prompt action and follow the appropriate response steps to minimize the impact and recover data. Firstly, it’s crucial to disconnect the infected system from the internet to prevent further propagation of the ransomware throughout the network. Next, you must identify the type of ransomware via its extension or ransom note left on the system. It’s important to gather as much information as possible about the ransomware to determine the appropriate response.


If adequate backups of the affected data are available, it’s essential to restore them immediately. Ensure that you verify their integrity and perform a scan for any remaining traces of the ransomware. If backups aren’t available, consult with IT security professionals for possible decryption tools or approaches. However, using decryption tools can be risky and may result in additional system damage, so it should only be attempted under expert guidance.


If ransom payment is considered, it is strongly advised to consult law enforcement and IT security experts before proceeding. Ransom payment may not guarantee the safe recovery of data and can incentivize further ransomware attacks. After recovery, it’s essential to assess and improve system security to prevent future ransomware threats. Regularly updating software, implementing firewalls and antivirus programs, and educating employees on best cybersecurity practices can significantly reduce the risk of ransomware attacks.


To sum it up, responding to ransomware requires a quick response, identifying the ransomware type, restoring backups, consulting IT security professionals for decryption, considering legal and expert advice before making ransom payment, and implementing improved system security measures. Taking these steps can ensure an effective response to ransomware attacks and protect data from future threats.

Soc in a Box

Published 16/10/2017 / by jeff / Leave a Comment
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Well not really, but I’m going to write a series of posts that will all tie together, which can be a very useful tool for anyone interested in having a security home lab, or even in a new or established security operations centre.

I am going to be using open source software, and showing how they can be used together and create a pretty awesome environment, that in my opinion rivals or if not better than many of the paid and expensive tools in the security industry.

Over the next few weeks and months, I will create guides for the following.

Cuckoo

The Hive

MISP

Security Onion

Elastic Stack

Google Rapid Response

I’m not necessary going to create guides in the order listed above, however I will be starting with cuckoo.

Cuckoo is a fun place to start as you can get a pretty awesome malware sandbox analysis tool up and running in a fairly short amount of time, and see real results and benefits from it.  There are so many ways you can customise it and get it working for how you want it in your own environment.  Why pay a 3rd party for your malware analysis when you can have a free and powerful version of your own.

Anyhow, enough jibber jabbing.  Time for the first update!

Boozallen Report on Petya

Published 13/07/2017 / by jeff / Leave a Comment
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I came across this write up by boozallen yesterday, and found it had some very interesting thoughts and insight to how and what happened.

 

https://www.boozallen.com/content/dam/boozallen_site/sig/pdf/white-paper/telebots-group-and-petya.pdf

 

1. Four VirusTotal users uploaded the compiled VBS backdoors along with other malicious files, including the
TeleBots telegram-based backdoor, PowerShell post-exploitation scripts, Mimikatz, and other tools. For each
user, these uploads occurred within the same one- to two-day time period.
2. In most cases, these files were uploaded several months prior to the 27 June Petya incident.
3. Booz Allen Cyber4Sight also determined that in several cases, these submitters also uploaded files
associated with the MEDoc update utility to VirusTotal. This shows that these submitters were also likely
users of the MEDoc software, and the inclusion of these files with the files identified in number 1 (above)
demonstrates that MEDoc-related processes may have facilitated the installation vector for this software.

 

These past few months have been quite interesting.  The scale and ease of WannaCry and the more recent  Petya/Non Petya attacks, have created a greater awareness for individuals outside of the security world.  Major news outlets are interested in these events as they transpire and this can only be a good thing.  I still believe we are many years away from individuals and business truly changing their mindsets and realise that just reacting to these events is not enough, and more time and effort is spent on how these applications are designed and how we approach security.  We need to try harder to make applications and hardware secure by design and not rely on 3rd party products afterwards to make the product “secure”.

We are going to have several more large scale events like this until the mindset changes, humans are stubborn and we do not like to change – however this is something we must do.

 

 

Talos Update on M.E.Doc

Published 05/07/2017 / by jeff / Leave a Comment
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http://blog.talosintelligence.com/2017/07/the-medoc-connection.html?m=1

Summary

The Nyetya attack was a destructive ransomware variant that affected many organizations inside of Ukraine and multinational corporations with operations in Ukraine. In cooperation with Cisco Advanced Services Incident Response, Talos identified several key aspects of the attack. The investigation found a supply chain-focused attack at M.E.Doc software that delivered a destructive payload disguised as ransomware. By utilizing stolen credentials, the actor was able to manipulate the update server for M.E.Doc to proxy connections to an actor-controlled server. Based on the findings, Talos remains confident that the attack was destructive in nature. The effects were broad reaching, with Ukraine Cyber police confirming over 2000 affected companies in Ukraine alone.
This is another good article and write up by Talos.
Gives a lot more useful insight as to how this happened, another good read, will be interesting to see how this continues to develop over the next few days and weeks.

Backdoor in M.E.Doc Application

Published 04/07/2017 / by jeff / Leave a Comment
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I came across an interesting article today, with regards to the Petya / NotPetya cyber attack from last week.  This is a very good write up and analysis of how the organisation M.E.Doc appears to have been compromised and used to spread the malware in a series of updates for the software it produces.

This demonstrates how devastating these types of compromises can be and as a defender can make it very difficult to identify and stop this type of attack from happening, if you happen to be the target of said attack.

I suggest you read this very good article!

 

https://www.welivesecurity.com/2017/07/04/analysis-of-telebots-cunning-backdoor/

Analysis of TeleBots’ cunning backdoor

On the 27th of June 2017, a new cyberattack hit many computer systems in Ukraine, as well as in other countries. That attack was spearheaded by the malware ESET products detect as Diskcoder.C(aka ExPetr, PetrWrap, Petya, or NotPetya). This malware masquerades as typical ransomware: it encrypts the data on the computer and demands $300 bitcoins for recovery. In fact, the malware authors’ intention was to cause damage, so they did all that they could to make data decryption very unlikely.

 

Another good write up by bleeping computer that contains more information.

 

https://www.bleepingcomputer.com/news/security/ukrainian-police-seize-servers-from-where-notpetya-outbreak-first-spread/

Conspiracy theories

Last week, a blog post from a Ukrainian web developer went viral, after it hinted that the real culprit behind the hacked server could have been M.E.Doc’s web host, Wnet, a company that has been accused of having ties to Russia’s intelligence service (FSB).

An investigation into the man’s accusations revealed that the SBU had raided the web host on June 1, for “illegal traffic routing to Crimea in favor of Russian special services.”

 

View of someone who was impacted by Petya

Published 28/06/2017 / by jeff / 3 Comments on View of someone who was impacted by Petya
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http://colsec.blogspot.de/2017/06/petya-outbreak-june-27th.html

 

My machine –

Domain joined Windows 10 Enterprise 64bit running McAfee AV + Encrypted HDD. Fully patched with June’s updates and manually disabled/removed SMBv1.

Hit at 12:40 UK time with a BSoD. Reboot “Please install operating system – no boot device”.

 

And the follow up

http://colsec.blogspot.de/2017/06/petyaa-infection-summary-of-events.html

 

I’ll just put this up here to summarise what happened and how.

We assume 1 PC was infected, that machine provided the virus with some credentials. Could have been a workstation admin’s account, giving the virus admin rights to all PCs in the local area. Over time, it must have picked up Domain Admin rights as it spread, then hitting Domain Controllers and all other Windows servers with it’s PSEXEC/WMIC code. The rest is history. We lost PCs that were encrypted with McAfee Disk Encryption due to corrupted MBR, PCs that were not encrypted with McAfee showed the ransom message.

 

This is a good demonstration of making sure everything is 100% patched and not nearly patched.  It is difficult to keep older machines patched and updated in an enterprise environment, however when these systems are designed and implemented, we should be thinking and taking into consideration how we are going to update them and keep them secure, otherwise we will have to deal with the events described above, again and again.

Do not pay to Petra Ransomware Email

Published 27/06/2017 / by jeff / Leave a Comment
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During the afternoon it emerged that the “PetrWrap/Petya” malware is currently spreading quickly in many places, including Ukraine.

Here are the facts that we can contribute to “PetrWrap/Petya”:
– Since midday it is no longer possible for the blackmailers to access the email account or send emails.
– Sending emails to the account is no longer possible either.

https://posteo.de/en/blog/info-on-the-petrwrappetya-ransomware-email-account-in-question-already-blocked-since-midday

It’s never a good idea to pay the ransom, even if they had the intention to give you your decryption code, they are not even going to be receiving  your email.

Patch and Backup.