This hypothesis posits that adversaries are deploying the CookieTools.exe utility to manipulate browser cookies for session hijacking or credential theft within Azure environments. Proactive hunting is essential because this specific Chinese hacktool often exhibits benign behavior initially, allowing it to evade standard signature-based detections while establishing a foothold for lateral movement.
rule CookieTools {
meta:
description = "Chinese Hacktool Set - file CookieTools.exe"
author = "Florian Roth"
reference = "http://tools.zjqhr.com/"
date = "2015-06-13"
hash = "b6a3727fe3d214f4fb03aa43fb2bc6fadc42c8be"
strings:
$s0 = "http://210.73.64.88/doorway/cgi-bin/getclientip.asp?IP=" fullword ascii
$s2 = "No data to read.$Can not bind in port range (%d - %d)" fullword wide
$s3 = "Connection Closed Gracefully.;Could not bind socket. Address and port are alread" wide
$s8 = "OnGetPasswordP" fullword ascii
$s12 = "http://www.chinesehack.org/" fullword ascii
condition:
uint16(0) == 0x5a4d and filesize < 5000KB and 2 of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 5 string patterns in its detection logic.
Here are 5 specific false positive scenarios for the Chinese Hacktool Set - file CookieTools.exe detection rule, including suggested filters and exclusions:
Scenario: Deployment of Enterprise Browser Extensions via Group Policy
CookieTools.exe to manage session cookies, clear cache, and enforce privacy policies across the domain. This file is often installed in %ProgramFiles%\Common Files\BrowserManager\ during a standard Group Policy Object (GPO) refresh.C:\Program Files\Common Files\BrowserManager\CookieTools.exe and restrict the alert to only trigger if the file hash does not match the known good SHA-256 hash of the enterprise-approved version.Scenario: Scheduled Maintenance Job for Digital Asset Management (DAM) Systems
CookieTools.exe to analyze and purge stale user session data from the application server’s temporary directory (C:\Temp\DAM_Maintenance\). The execution is triggered by a Windows Task Scheduler job named “Daily_DAM_Cleanup” running under the SYSTEM or a dedicated service account (e.g., svc_dam_admin).TaskScheduler.exe (or specifically svchost.exe with the Schedule service) and the execution time falls within the defined maintenance window (e.g., 02:00 – 04:00 local time).