# [MED] Four steps for hardening Amazon EKS security

**Source:** Snyk
**Published:** 2021-07-21
**Article:** https://snyk.io/blog/hardening-amazon-eks-security/

## Threat Profile

Snyk Blog In this article
Written by Kamil Potrec 
July 21, 2021
0 mins read In the first part of this blog series, we explored deploying Amazon EKS with Terraform , and looked at how to secure the initial RBAC implementation along with securing the Instance Metadata Service. In this second post, we’ll look at more best practices to harden Amazon EKS security, including the importance of dedicated continuous delivery IAM roles , multi-account architecture for Amazon EKS cluster isolation , and h…

## Indicators of Compromise (high-fidelity only)

- _No high-fidelity IOCs in the RSS summary._ If the source publishes a technical write-up with defanged IOCs in the body, those would be picked up automatically on the next pipeline run.

## MITRE ATT&CK Techniques

- **T1071.001** — Web Protocols
- **T1071.004** — DNS
- **T1204.002** — User Execution: Malicious File

## Kill chain phases observed

_(none detected from narrative keywords)_

## Recommended hunts

### Beaconing — periodic outbound to small set of destinations

`UC_BEACONING` · phase: **c2** · confidence: **Medium**

**Splunk SPL (CIM):**
```spl
| tstats `summariesonly` count, values(All_Traffic.dest_port) AS ports
    from datamodel=Network_Traffic.All_Traffic
    where All_Traffic.action="allowed" AND All_Traffic.dest_category!="internal"
    by _time span=10s, All_Traffic.src, All_Traffic.dest
| `drop_dm_object_name(All_Traffic)`
| streamstats current=f last(_time) AS prev_time by src, dest
| eval delta = _time - prev_time
| stats avg(delta) AS avg_delta stdev(delta) AS sd_delta count by src, dest
| where count > 30 AND sd_delta < 5 AND avg_delta>=30 AND avg_delta<=600
| sort - count
```

**Defender KQL:**
```kql
DeviceNetworkEvents
| where Timestamp > ago(1d)
| where RemoteIPType == "Public" and ActionType == "ConnectionSuccess"
| project DeviceName, RemoteIP, RemotePort, Timestamp
| sort by DeviceName asc, RemoteIP asc, RemotePort asc, Timestamp asc
| extend prev_dev = prev(DeviceName, 1), prev_ip = prev(RemoteIP, 1),
         prev_port = prev(RemotePort, 1), prev_ts = prev(Timestamp, 1)
| where DeviceName == prev_dev and RemoteIP == prev_ip and RemotePort == prev_port
| extend delta_sec = datetime_diff('second', Timestamp, prev_ts)
| summarize conn_count = count(), avg_delta = avg(delta_sec), stdev_delta = stdev(delta_sec)
    by DeviceName, RemoteIP, RemotePort
| where conn_count > 30 and avg_delta between (30.0 .. 600.0) and stdev_delta < 5.0
| order by conn_count desc
```

### Article-specific behavioural hunt — Four steps for hardening Amazon EKS security

`UC_2813_1` · phase: **install** · confidence: **High**

**Splunk SPL (CIM):**
```spl
``` Article-specific bespoke detection — Four steps for hardening Amazon EKS security ```
| tstats `summariesonly` count
    from datamodel=Endpoint.Filesystem
    where Filesystem.action IN ("created","modified")
      AND (Filesystem.file_path="*/etc/kubernetes/authenticator/apiserver-webhook-kubeconfig.yaml*")
    by Filesystem.dest, Filesystem.user, Filesystem.process_name,
       Filesystem.file_path, Filesystem.file_name
| `drop_dm_object_name(Filesystem)`
```

**Defender KQL:**
```kql
// Article-specific bespoke detection — Four steps for hardening Amazon EKS security
// Hunts the actual binaries / paths / commandline fragments named
// in the article instead of a generic technique-class template.

// File-creation events for the named binaries / paths
DeviceFileEvents
| where Timestamp > ago(30d)
| where ActionType in ("FileCreated","FileModified")
| where (FolderPath has_any ("/etc/kubernetes/authenticator/apiserver-webhook-kubeconfig.yaml"))
| project Timestamp, DeviceName, AccountName, FolderPath,
          FileName, ActionType, InitiatingProcessFileName,
          InitiatingProcessCommandLine
| order by Timestamp desc
```


## Why this matters

Severity classified as **MED** based on: 2 use case(s) fired, 3 technique(s) inferred. Read the full article for actor attribution, tooling details, and any defanged IOCs in the body that aren't visible in the RSS summary.