This detection targets adversaries leveraging the ProxyTool2 utility to establish covert command-and-control channels or exfiltrate data through proxy configurations within the Azure environment. Proactively hunting for this behavior allows the SOC team to identify early-stage reconnaissance activities and validate legitimate usage patterns before low-severity signals are overlooked in routine monitoring.
rule ProxyTool2
{
strings:
$STR1 = { 82 F4 DE D4 D3 C2 CA F5 C8 C8 D3 82 FB F4 DE D4 D3 C2 CA 94 95 FB D4 D1 C4 CF C8 D4 D3 89 C2 DF C2 87 8A CC 87 00 } // '%SystemRoot%\System32\svchost.exe -k' xor A7
condition:
(uint16(0) == 0x5A4D or uint16(0) == 0xCFD0 or uint16(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 1 string patterns in its detection logic.
Here are 4 specific false positive scenarios for the ProxyTool2 detection rule in an enterprise environment, including suggested filters or exclusions:
Scenario: Scheduled Antivirus Definition Updates via Proxy
ProxyTool2 to route traffic through the corporate firewall before reaching vendor servers.C:\Program Files\CrowdStrike\csfalcon.exe spawning a child process named ProxyTool2.exe) running during off-peak maintenance windows (01:00–05:00 local time).Scenario: IT Admin Deployment of Browser Extensions
ProxyTool2 to configure proxy settings on user endpoints. This is often triggered by a scheduled Group Policy Object (GPO) refresh or an SCCM task sequence.ccmexec.exe (System Center Configuration Manager) or msiexec.exe, specifically when the user account is a Domain Admin group member (e.g., DOMAIN\IT_Ops_Group).Scenario: Legacy Application License Verification
ProxyTool2 as a middleware component to perform daily license