How can we uncover shadow accounts across SaaS, cloud, and legacy systems?

Instead of investigating applications one at a time, work backward from the activity and spending trail. Start by reviewing a year of corporate card and accounts-payable data for SaaS vendors, then compare it with identity-provider enterprise applications and sign-in logs. That helps uncover services with active users but no assigned owner or provisioning history. Proxy and DNS logs are useful too—new SaaS domains with a steady stream of users often reveal teams that created accounts outside the normal process.

A unified identity-discovery platform can reduce the integration burden by correlating accounts across SaaS, cloud, and older systems. That gives you a broader starting inventory and lets you focus manual investigation on ownership, access, and remediation instead of connecting every application separately.

Email telemetry can provide another useful signal. Search mail logs for messages sent from vendor domains or recognizable service addresses, then investigate the users receiving them. This can expose accounts and tools that do not appear in your official application inventory.

Audit OAuth grants through your identity provider. This often catches more shadow services than SaaS-specific discovery because employees may have signed in with a corporate Google or Microsoft account without going through IT provisioning. It is a good starting point before building integrations for individual applications.