Roshal Archive (RAR) or PowerShell File Downloaded from the Internet
editRoshal Archive (RAR) or PowerShell File Downloaded from the Internet
editDetects 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 TTPs. This may be atypical behavior for a managed network and can be indicative of malware, exfiltration, or command and control.
Rule type: query
Rule indices:
- packetbeat-*
Severity: medium
Risk score: 47
Runs every: 5 minutes
Searches indices from: now-6m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Network
- Threat Detection
- Command and Control
Version: 1
Added (Elastic Stack release): 7.10.0
Rule authors: Elastic
Rule license: Elastic License
Potential false positives
editDownloading 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.
Investigation guide
editThis activity has been observed in FIN7 campaigns.
Rule query
editevent.category:(network OR network_traffic) AND network.protocol:http AND url.path:/.*(rar|ps1)/ AND source.ip:(10.0.0.0\/8 OR 172.16.0.0\/12 OR 192.168.0.0\/16)
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Command and Control
- ID: TA0011
- Reference URL: https://attack.mitre.org/tactics/TA0011/
-
Technique:
- Name: Ingress Tool Transfer
- ID: T1105
- Reference URL: https://attack.mitre.org/techniques/T1105/