Heroes, Good morning! Here's a detailed and fully link-checked look at the current cybersecurity landscape for Friday, August 8, 2025.
CRITICAL ITEMS
HIGH SEVERITY ITEMS
EXECUTIVE INSIGHTS
VENDOR SPOTLIGHTToday's top threat is the active exploitation of the WinRAR zero-day vulnerability, CVE-2025-8088, a client-side attack that bypasses perimeter defenses. This scenario highlights the critical importance of endpoint security that can detect and block malicious behaviors, not just known file signatures. For this reason, we are spotlighting SentinelOne and its Singularity Platform, which excels at behavioral AI-based threat detection on the endpoint.
Threat Context: WinRAR Zero-Day Exploited to Install Malware (CVE-2025-8088)
Platform Focus: SentinelOne Singularity Platform
Summary & Significance: SentinelOne's approach does not rely solely on file-based signatures, which are ineffective against zero-day exploits. Instead, its behavioral AI engine monitors process execution chains in real-time. It can identify and block the malicious activity that occurs *after* the vulnerability is exploited—such as `WinRAR.exe` spawning a suspicious `powershell.exe` or `cmd.exe` process to download a second-stage payload like RomCom.
// Hunt for WinRAR spawning command-line interpreters or downloaders
ProcessName = "WinRAR.exe" AND ChildProcessName IN ("powershell.exe", "cmd.exe", "rundll32.exe", "msiexec.exe", "bitsadmin.exe")Vendor Resources: SentinelOne Blog: The Good, the Bad and the Ugly in Cybersecurity
DETECTION & RESPONSE KIT# Hunt for WinRAR spawning suspicious child processes
sourcetype=Sysmon EventCode=1 ParentImage="*\\WinRAR.exe" Image IN ("*\\powershell.exe", "*\\cmd.exe", "*\\rundll32.exe")
| stats count by ParentImage, Image, CommandLine, User, host/*
Author: Cybersecurity Rundown
Date: 2025-08-08
Description: Detects RomCom RAT based on unique PDB path and strings.
Severity: Critical
*/
rule Malware_Win_RomCom_RAT {
meta:
description = "Identifies RomCom RAT payload"
author = "Cybersecurity Rundown"
date = "2025-08-08"
reference = "https://www.bleepingcomputer.com/news/security/winrar-zero-day-flaw-exploited-by-romcom-hackers-in-phishing-attacks/"
strings:
$pdb = "C:\\Users\\admin\\Desktop\\work\\Client\\x64\\Release\\Client.pdb" ascii
$str1 = "StartWork" wide
$str2 = "GetFileFromURL" wide
$str3 = "GetScreen" wide
condition:
uint16(0) == 0x5a4d and (1 of them)
}# Remotely check WinRAR version on a list of servers
$computers = "server1", "server2", "server3"
$vulnerable_version = "6.23" # Example version, replace with actual last-vulnerable version
foreach ($comp in $computers) {
if (Test-Connection -ComputerName $comp -Count 1 -Quiet) {
$path = "HKLM:\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\App Paths\\WinRAR.exe"
$winrar_path = (Get-ItemProperty -Path $path -ComputerName $comp -ErrorAction SilentlyContinue)."(default)"
if ($winrar_path) {
$version = (Get-Item -Path $winrar_path).VersionInfo.ProductVersion
if ([version]$version -lt [version]$vulnerable_version) {
Write-Host "VULNERABLE: $comp has WinRAR version $version"
} else {
Write-Host "OK: $comp has WinRAR version $version"
}
} else {
Write-Host "INFO: WinRAR not found on $comp"
}
} else {
Write-Host "ERROR: Cannot connect to $comp"
}
}This rundown should provide a solid overview of the current threat landscape. Thank you to all our cyberheroes for your diligence and hard work. Stay vigilant!