RansomHub hits via RDP password spray
A password spray against exposed RDP led to credential theft, lateral movement across domain controllers, Rclone exfiltration of 2GB, and RansomHub ransomware deployment over SMB in 118 hours.
In November 2024, a threat actor conducted a four-hour password spray attack against an internet-facing RDP server, successfully compromising six accounts. Using one account with elevated privileges, they deployed Mimikatz and NirSoft CredentialsFileView to harvest credentials from LSASS memory and stored credential files. The actor leveraged RDP to move laterally to domain controllers, where they accessed DNS management consoles and continued credential harvesting across child domains. Discovery was accomplished through living-off-the-land binaries (net, nltest, nslookup) and third-party tools including Advanced IP Scanner and SoftPerfect NetScan.
Over the following days, the threat actor installed Atera and Splashtop for persistent remote access on backup servers. On day three, they deployed Rclone with helper scripts to exfiltrate 2.03 GB of documents, spreadsheets, emails, and images over SFTP to 38.180.245.207:443. The actor reset multiple user passwords across domain controllers before the final stage. On day six, they deployed RansomHub ransomware (amd64.exe) which propagated via SMB to remote hosts using automated remote service execution. The ransomware killed running VMs, deleted shadow copies, cleared event logs, and encrypted files network-wide. Time to ransomware was approximately 118 hours across six calendar days, demonstrating methodical preparation before impact operations.
Mentioned in this report
Detection guidance
Credential Dumping Tool Execution (Mimikatz / NirSoft CredentialsFileView)
Detects execution of known LSASS credential-harvesting tools (Mimikatz, NirSoft CredentialsFileView) observed after RDP-based lateral movement. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.
title: Credential Dumping Tool Execution (Mimikatz / NirSoft CredentialsFileView)
id: 2e2602f3-ad26-582a-a502-03497e290595
status: experimental
description: Detects process execution or command-line indicators of Mimikatz or NirSoft
CredentialsFileView used to harvest credentials from LSASS memory or stored credential
files, as seen in RansomHub intrusions following RDP compromise.
references:
- RansomHub RDP password spray intrusion report
logsource:
category: process_creation
product: windows
detection:
selection_mimikatz:
- CommandLine|contains:
- sekurlsa::logonpasswords
- 'sekurlsa::'
- 'lsadump::'
- privilege::debug
- Image|endswith:
- \mimikatz.exe
selection_nirsoft:
Image|endswith: \CredentialsFileView.exe
condition: 1 of selection_*
falsepositives:
- Authorized penetration testing or red team engagements using Mimikatz
- Legitimate use of NirSoft utilities by IT staff for credential recovery (rare in
production environments)
level: high
tags:
- attack.t1003.001
- attack.credential_access
author: Vorant
Domain Trust and Account Discovery via LOLBins Chain
Detects sequential use of nltest, net, and nslookup to enumerate domain trusts, groups, and DNS infrastructure across child domains, matching post-compromise discovery activity. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.
title: Domain Trust and Account Discovery via LOLBins Chain
id: 34f97ff2-aa74-5989-89f4-62c027a18be5
status: experimental
description: Detects living-off-the-land discovery commands (nltest domain trusts/dclist
enumeration, net group domain queries, nslookup) frequently used together by threat
actors after gaining domain admin or elevated access via RDP lateral movement.
references:
- RansomHub RDP password spray intrusion report
logsource:
category: process_creation
product: windows
detection:
selection_nltest:
Image|endswith: \nltest.exe
CommandLine|contains:
- /domain_trusts
- /dclist
- /trusted_domains
selection_net_group:
Image|endswith: \net.exe
CommandLine|contains:
- group
- /domain
selection_nslookup:
Image|endswith: \nslookup.exe
condition: 1 of selection_*
falsepositives:
- IT administrators troubleshooting DNS or domain trust relationships
- Scheduled scripts performing routine domain health checks
level: medium
tags:
- attack.t1482
- attack.t1087.002
- attack.t1069.002
- attack.discovery
author: Vorant
Shadow Copy Deletion and Windows Event Log Clearing Prior to Ransomware Impact
Detects the combination of shadow copy/backup deletion and event log clearing commands typically executed immediately before ransomware encryption to inhibit recovery and remove forensic evidence. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.
title: Shadow Copy Deletion and Windows Event Log Clearing Prior to Ransomware Impact
id: 1fa85ac1-0c1e-53f6-a44f-8379225bc418
status: experimental
description: Detects vssadmin/wbadmin shadow copy or backup catalog deletion combined
with wevtutil event log clearing, a pattern used by RansomHub and similar ransomware
operators immediately before encrypting files network-wide.
references:
- RansomHub RDP password spray intrusion report
logsource:
category: process_creation
product: windows
detection:
selection_shadow_delete:
Image|endswith:
- \vssadmin.exe
- \wbadmin.exe
- \wmic.exe
CommandLine|contains:
- delete shadows
- delete catalog
- shadowcopy delete
- resize shadowstorage
selection_log_clear:
Image|endswith: \wevtutil.exe
CommandLine|contains:
- 'cl '
- clear-log
- ' cl system'
- ' cl security'
- ' cl application'
condition: selection_shadow_delete or selection_log_clear
falsepositives:
- Legitimate backup software performing scheduled shadow copy maintenance (rare to
combine with log clearing)
- System administrators clearing logs for disk space management (uncommon and should
be verified)
level: high
tags:
- attack.t1490
- attack.t1070.001
- attack.t1070
- attack.impact
author: Vorant
Behavioural rules are generated from public reporting — validate in your environment before deploying.
Source reporting: https://thedfirreport.com/2025/06/30/hide-your-rdp-password-spray-leads-to-ransomhub-deployment
This is the public brief
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