How to Defend Government Systems Against Intensifying Cyberattacks

Recent reports from Dark Reading highlight a troubling trend: cyberattacks are intensifying pressure on Latin American governments. From disruptive incidents in Puerto Rico to a surge of reconnaissance probes targeting Colombia’s health sector, state-sponsored and criminal actors are increasingly exploiting vulnerabilities in public infrastructure.

For security teams defending government networks and healthcare providers, this underscores a critical need for heightened vigilance. This post analyzes the threat landscape and provides actionable detection rules and remediation steps to harden your defenses against these escalating attacks.

Introduction

Cyber threats against Latin American government entities are evolving from nuisance-level disruptions to critical infrastructure threats. The recent wave of attacks, including the targeting of Colombia's health sector, suggests a systematic effort to probe for weaknesses in legacy systems and public-facing services. For defenders, this means the traditional "set it and forget it" approach to perimeter security is no longer sufficient. We must assume probing is constant and that breach attempts are imminent.

Technical Analysis

The attacks described in the recent reports typically follow a pattern of initial reconnaissance, followed by exploitation, and then disruption.

• Reconnaissance: Attackers perform extensive scanning (probing) of government and health sector IP ranges to identify exposed services like RDP, SQL databases, and unpatched web servers.
• Exploitation: Once a vulnerability is identified—often a known CVE in legacy software or a brute-forced credential—actors gain a foothold. In the health sector, this often targets medical devices or database servers holding sensitive PII.
• Impact: The goal ranges from data exfiltration (espionage) to operational disruption (ransomware or DDoS). The "disruptive attacks" in Puerto Rico suggest the latter, aimed at degrading public trust and service availability.

Severity: High. The targeting of healthcare and essential government services poses direct risks to public safety and national stability.

Patch/Fix Status: While specific CVEs for the recent probes vary by target, the primary defense is patching known vulnerabilities in VPN concentrators, remote access services, and database management systems.

Defensive Monitoring

To detect these threats early, security operations centers (SOCs) should implement hunting strategies focused on reconnaissance tools, lateral movement, and ransomware precursors. Below are detection rules for SIGMA, KQL, and Velociraptor, along with PowerShell scripts for verification.

SIGMA Rules

These SIGMA rules are designed to detect common behaviors associated with government-targeting threat actors: active reconnaissance (scanning) and defense evasion (clearing logs).

---
title: Suspicious Reconnaissance Tool Execution
id: 3b2f1e4d-5a6b-4c7d-8e9f-1a2b3c4d5e6f
status: experimental
description: Detects the execution of common network reconnaissance tools often used during the probing phase of attacks against government networks.
references:
  - https://attack.mitre.org/techniques/T1595/
author: Security Arsenal
date: 2024/05/23
tags:
  - attack.reconnaissance
  - attack.t1595.001
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|contains:
      - '\nmap.exe'
      - '\netcat.exe'
      - '\nc.exe'
      - '\masscan.exe'
      - '\nslookup.exe'
  condition: selection
falsepositives:
  - Legitimate network administration by authorized staff
level: medium
---
title: Clear Windows System Logs via Wevtutil
id: a1b2c3d4-e5f6-4a7b-8c9d-1e2f3a4b5c6d
status: experimental
description: Detects attempts to clear Windows event logs using wevtutil, a common tactic used by attackers to hide probing activity and lateral movement.
references:
  - https://attack.mitre.org/techniques/T1070/
author: Security Arsenal
date: 2024/05/23
tags:
  - attack.defense_evasion
  - attack.t1070.001
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith: '\wevtutil.exe'
    CommandLine|contains: 'clear-log'
  condition: selection
falsepositives:
  - System administrators performing maintenance
level: high
---
title: Potential Ransomware Prelude - Volume Shadow Copy Deletion
id: b2c3d4e5-f6a7-5b8c-9d0e-2f3a4b5c6d7e
status: experimental
description: Detects commands used to delete Volume Shadow Copies, which often occurs immediately before data encryption in ransomware attacks targeting government data.
references:
  - https://attack.mitre.org/techniques/T1490/
author: Security Arsenal
date: 2024/05/23
tags:
  - attack.impact
  - attack.t1490
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    Image|endswith:
      - '\vssadmin.exe'
      - '\wmic.exe'
    CommandLine|contains:
      - 'delete shadows'
      - 'shadowstorage delete'
  condition: selection
falsepositives:
  - Rare system maintenance tasks
level: critical

KQL Queries (Microsoft Sentinel/Defender)

Use these KQL queries to hunt for suspicious network traffic and process execution patterns associated with the recent threat landscape.

// Hunt for mass scanning or probing behavior from internal hosts
DeviceNetworkEvents
| where Timestamp > ago(7d)
| where ActionType == "ConnectionSuccess" or ActionType == "ConnectionAttempt"
| summarize DistinctDestinations = dcount(RemoteIP), Destinations = make_set(RemoteIP, 100) by DeviceName, InitiatingProcessFileName, bin(Timestamp, 1h)
| where DistinctDestinations > 50
| project DeviceName, InitiatingProcessFileName, DistinctDestinations, Timestamp
// Hunt for execution of common hacking tools
DeviceProcessEvents
| where Timestamp > ago(24h)
| where ProcessCommandLine has "vssadmin" or ProcessCommandLine has "wevtutil" 
| where ProcessCommandLine has "delete"
| project Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessFileName

Velociraptor VQL

These Velociraptor hunts help identify if probing tools have been executed on endpoints or if logs have been cleared.

-- Hunt for process execution of reconnaissance tools
SELECT Pid, Name, CommandLine, Exe, Username, CreateTime
FROM pslist()
WHERE Name =~ 'nmap' 
   OR Name =~ 'masscan'
   OR Name =~ 'netcat'
   OR Name =~ 'nc.exe'
   OR CommandLine =~ 'clear-log'

-- Hunt for recent VSS Shadow Deletion attempts in PowerShell Script Block Logs
SELECT System.TimeCreated, UserData.Message
FROM parse_xml(filename='C:\Windows\System32\winevt\Logs\Microsoft-Windows-PowerShell%4Operational.evtx')
WHERE UserData.Message =~ 'delete' AND UserData.Message =~ 'shadow'

PowerShell Verification Script

This script can be used by IT admins to check for the presence of common scanning tools or signs of log clearing on Windows endpoints.

# Check for common scanning tools in PATH and recent execution
$suspiciousProcesses = @('nmap.exe', 'masscan.exe', 'netcat.exe', 'nc.exe', 'putty.exe')

Get-Process | Where-Object { $suspiciousProcesses -contains $_.ProcessName } | 
    Select-Object ProcessName, Id, StartTime, Path | 
    Format-Table -AutoSize

# Check for event log clear events (Event ID 1102) within the last 7 days
$startTime = (Get-Date).AddDays(-7)
Get-WinEvent -FilterHashtable @{LogName='Security'; ID=1102; StartTime=$startTime} -ErrorAction SilentlyContinue | 
    Select-Object TimeCreated, Message | 
    Format-List

Remediation

To protect your organization against these intensifying threats, implement the following steps immediately:

1. Patch Public-Facing Infrastructure: Prioritize patching for VPN appliances (e.g., Pulse Secure, Fortinet, Citrix) and web servers exposed to the internet. These are the primary entry points for the "probes" reported in Colombia.
2. Disable Unused RDP Ports: Ensure RDP is not exposed directly to the internet. Force all remote access through a VPN with MFA.
3. Implement Network Segmentation: Separate sensitive healthcare/government data (PII) from general administrative networks. This limits the blast radius if a probe turns into a breach.
4. Audit Backup Configurations: Ensure offline backups are immutable and tested. Verify that vssadmin access is restricted to administrators only.
5. Enable MFA Everywhere: Compromised credentials are a top vector. Multi-factor authentication is the single most effective control against credential stuffing attacks.

Related Resources

Security Arsenal Alert Triage Automation AlertMonitor Platform Book a SOC Assessment platform Intel Hub