Orphaned Service Accounts Threaten Microsoft 365 Security in Chile

Security researchers have highlighted a growing risk in Chilean enterprises: abandoned or poorly managed service accounts that can bypass even the most stringent user authentication controls, granting attackers unrestricted access to Microsoft 365 environments.

The issue surfaced in a recent analysis published by Dark Reading, which documented how threat actors exploited “ghost” service accounts—legacy credentials left over from decommissioned applications or forgotten automation scripts—to harvest email, files, and other cloud data without triggering typical user‑account alerts.

Unlike regular employee accounts, service accounts often lack multi‑factor authentication, have elevated privileges, and are exempt from standard password‑rotation policies. When these accounts are not regularly audited, they become attractive footholds for malicious actors seeking to move laterally across an organization’s tenant.

In the Chilean cases examined, attackers first obtained a low‑level credential through phishing or credential‑stuffing attacks. They then leveraged that access to locate dormant service accounts within Azure Active Directory, reset their passwords, and use the accounts to download sensitive documents, read mailbox contents, and exfiltrate data to external servers.

Experts warn that the problem is not limited to Chile. Globally, many firms rely on service accounts for automation, backup, and integration tasks, and the rapid adoption of cloud productivity suites has outpaced the development of comprehensive governance frameworks for these identities.

Mitigation strategies include implementing strict lifecycle management for service accounts, enforcing MFA where possible, and employing conditional access policies that flag anomalous sign‑ins from accounts that rarely authenticate. Continuous monitoring tools that can differentiate between human and service‑account activity are also becoming essential.

Regulators and industry bodies are beginning to issue guidance on cloud‑account hygiene, but the onus remains on organizations to conduct regular inventories, retire unused credentials, and integrate service‑account oversight into broader security operations.

As cloud adoption continues to expand, the hidden risk posed by forgotten service accounts is likely to attract more attention from both attackers and defenders, prompting a shift toward more automated credential‑management solutions and tighter policy enforcement.