Roshal Archive (RAR) or PowerShell File Downloaded from the Internet

Last updated a year ago on 2025-01-15

Created 6 years ago on 2020-07-02

About

Detects a Roshal Archive (RAR) file or PowerShell script downloaded from the internet by an internal host. Gaining initial access to a system and then downloading encoded or encrypted tools to move laterally is a common practice for adversaries as a way to protect their more valuable tools and tactics, techniques, and procedures (TTPs). This may be atypical behavior for a managed network and can be indicative of malware, exfiltration, or command and control.

Tags

Use Case: Threat DetectionTactic: Command and ControlDomain: EndpointData Source: PAN-OSLanguage: kuery

Severity

medium

Risk Score

MITRE ATT&CK™

Command and Control (TA0011)(external, opens in a new tab or window)

↳ Ingress Tool Transfer (T1105)(external, opens in a new tab or window)

False Positive Examples

Downloading RAR or PowerShell files from the Internet may be expected for certain systems. This rule should be tailored to either exclude systems as sources or destinations in which this behavior is expected.

License

Elastic License v2(external, opens in a new tab or window)

Definition

Rule Type

Query (Kibana Query Language)

Integration Pack

Prebuilt Security Detection Rules

Index Patterns

packetbeat-*auditbeat-*filebeat-*logs-network_traffic.*logs-panw.panos*

Related Integrations

network_traffic(external, opens in a new tab or window)

panw(external, opens in a new tab or window)

Query

✄𐘗text code block:
✄𐘗(event.dataset: (network_traffic.http or network_traffic.tls) or
  (event.category: (network or network_traffic) and network.protocol: http)) and
  (url.extension:(ps1 or rar) or url.path:(*.ps1 or *.rar)) and
    not destination.ip:(
      10.0.0.0/8 or
      127.0.0.0/8 or
      169.254.0.0/16 or
      172.16.0.0/12 or
      192.0.0.0/24 or
      192.0.0.0/29 or
      192.0.0.8/32 or
      192.0.0.9/32 or
      192.0.0.10/32 or
      192.0.0.170/32 or
      192.0.0.171/32 or
      192.0.2.0/24 or
      192.31.196.0/24 or
      192.52.193.0/24 or
      192.168.0.0/16 or
      192.88.99.0/24 or
      224.0.0.0/4 or
      100.64.0.0/10 or
      192.175.48.0/24 or
      198.18.0.0/15 or
      198.51.100.0/24 or
      203.0.113.0/24 or
      240.0.0.0/4 or
      "::1" or
      "FE80::/10" or
      "FF00::/8"
    ) and
    source.ip:(
      10.0.0.0/8 or
      172.16.0.0/12 or
      192.168.0.0/16
    )

Install detection rules in Elastic Security

Detect Roshal Archive (RAR) or PowerShell File Downloaded from the Internet in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).