Computer-implemented penetration test method for checking the vulnerability of a computer system , comprising (i) providing a proxy service on a computer, wherein the proxy service comprises a connection framework which is designed to connect the proxy service to a plurality of different vulnerability testing machines that are implemented via specific proprietary computer applications, (ii) acquiring an address data signal which represents a network address of a network application in a network , which network application is executed on the computer system to be tested, (iii) determining additional network addresses of the network application in the network , (iv) obtaining initial request data signals from the vulnerability testing machines by means of the proxy service via the connection framework of the proxy service , wherein the initial request data signals each represent an initial request of the associated vulnerability testing machines to the network application , (v) forwarding the initial request data signals to the network application by means of the proxy service via the network , (vi) obtaining initial response data signals from the network application to the forwarded initial request data signal by means of the proxy service via the network , wherein the initial response data signals each represent an initial response of the network application to the initial request of the associated vulnerability testing machine , (vii) generating extended initial response data signals by means of the proxy service by adding the additional network addresses to the initial response data signals, and (viii) transmitting the extended initial response data signals to the plurality of vulnerability testing machines. (i) providing a proxy service on a computer, wherein the proxy service comprises a connection framework which is designed to connect the proxy service to a plurality of different vulnerability testing machines that are implemented via specific proprietary computer applications, (ii) acquiring an address data signal which represents a network address of a network application in a network , which network application is executed on the computer system to be tested, (iii) determining additional network addresses of the network application in the network , (iv) obtaining initial request data signals from the vulnerability testing machines by means of the proxy service via the connection framework of the proxy service , wherein the initial request data signals each represent an initial request of the associated vulnerability testing machines to the network application , (v) forwarding the initial request data signals to the network application by means of the proxy service via the network , (vi) obtaining initial response data signals from the network application to the forwarded initial request data signal by means of the proxy service via the network , wherein the initial response data signals each represent an initial response of the network application to the initial request of the associated vulnerability testing machine , (vii) generating extended initial response data signals by means of the proxy service by adding the additional network addresses to the initial response data signals, and (viii) transmitting the extended initial response data signals to the plurality of vulnerability testing machines. <EOS>