List inboxes that recieved an ISO attachment


Description

Adversaries may use ISO files as email attachment to trick users into opening those malicious files. Trend Micro has done reaches on spam campgains that use ISO image files to deliver Lokibot and NanoCore malware onto victems devices. Recieving the ISO does not mean that the user is infected, depending on the malware, the user is mostly only infected after the ISO has been mapped or if files on the ISO have been opened. This query detects all inbound emails that contain a ISO image.

By default ISO files are blocked in Exchange, your admin can unblock those file extensions. Thus this query should only trigger if a ISO is recieved and your admin has configured your environment in a way that ISO files are accepted.

Query · kql

EmailEvents
| where EmailDirection == 'Inbound'
| join kind=inner EmailAttachmentInfo on NetworkMessageId
| project
     Timestamp,
     NetworkMessageId,
     SenderFromAddress,
     SenderIPv4,
     SenderIPv6,
     RecipientEmailAddress,
     Subject,
     FileName,
     FileType,
     ThreatNames
| where FileName endswith ".iso"
Raw source List inboxes that recieved an ISO attachment · KQL
Esc
Published by Bert-JanP/Hunting-Queries-Detection-Rules ↗, licensed under BSD 3-Clause ↗. Reproduced here unmodified.
# List inboxes that recieved an ISO attachment

## Query Information

#### Description
Adversaries may use ISO files as email attachment to trick users into opening those malicious files. Trend Micro has done reaches on spam campgains that use ISO image files to deliver Lokibot and NanoCore malware onto victems devices. Recieving the ISO does not mean that the user is infected, depending on the malware, the user is mostly only infected after the ISO has been mapped or if files on the ISO have been opened. This query detects all inbound emails that contain a ISO image. 

By default ISO files are blocked in Exchange, your admin can unblock those file extensions. Thus this query should only trigger if a ISO is recieved and your admin has configured your environment in a way that ISO files are accepted. 

#### Risk
A user opens the ISO file that contains malware and grants the adversery initial access to the network.

#### References
- https://www.netskope.com/blog/lokibot-nanocore-iso-disk-image-files
- https://www.trendmicro.com/vinfo/it/security/news/cybercrime-and-digital-threats/malicious-spam-campaign-uses-iso-image-files-to-deliver-lokibot-and-nanocore
- https://support.microsoft.com/en-us/office/blocked-attachments-in-outlook-434752e1-02d3-4e90-9124-8b81e49a8519

## Defender XDR
```
EmailEvents
| where EmailDirection == 'Inbound'
| join kind=inner EmailAttachmentInfo on NetworkMessageId
| project
     Timestamp,
     NetworkMessageId,
     SenderFromAddress,
     SenderIPv4,
     SenderIPv6,
     RecipientEmailAddress,
     Subject,
     FileName,
     FileType,
     ThreatNames
| where FileName endswith ".iso"
```

## Sentinel
```
EmailEvents
| where EmailDirection == 'Inbound'
| join kind=inner EmailAttachmentInfo on NetworkMessageId
| project
     TimeGenerated,
     NetworkMessageId,
     SenderFromAddress,
     SenderIPv4,
     SenderIPv6,
     RecipientEmailAddress,
     Subject,
     FileName,
     FileType,
     ThreatNames
| where FileName endswith ".iso"
```

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