Traceroute is often used to help diagnose when users experience issues with Internet applications or services. Unfortunately, probes issued by classic traceroute tools differ from application traffic and hence can be treated differently by routers that perform load balancing and middleboxes within the network. This paper proposes a new tracer-oute tool, called Service traceroute. Service traceroute leverages the idea from paratrace, which passively listens to application traffic to then issue traceroute probes that pretend to be part of the application flow. We extend this idea to work for modern Internet services with support for identifying the flows to probe automatically, for tracing of multiple concurrent flows, and for UDP flows. We implement command-line and library versions of Service traceroute, which we release as open source. This paper also presents an evaluation of Service traceroute when tracing paths traversed by Web downloads from the top-1000 Alexa websites and by video sessions from Twitch and Youtube. Our evaluation shows that Service traceroute has no negative effect on application flows. Our comparison with Paris traceroute shows that a typical traceroute tool that launches a new flow to the same destination discovers different paths than when embedding probes in the application flow in a significant fraction of experiments (from 40% to 50% of our experiments in PlanetLab Europe).