Attack Path Analysis of Privileged Identity Compromise

Key judgments

Privileged identity compromise is a path problem, not an account problem. Hardening each admin account leaves the routes between accounts untouched: sync servers, trust relationships, application permissions and delegated reset rights. Attackers use those routes.
Hybrid identity links are the most valuable choke points. In the Storm-0501 intrusion documented by Microsoft, a directory sync server without endpoint protection led to a cloud Global Administrator and then to every Azure subscription in the enterprise. Confidence: high that the chain is real, moderate that it generalizes.
Non-human identities and app permissions sit outside most privileged access reviews. In the Midnight Blizzard case documented by Microsoft, a password spray on a legacy test account without MFA led, through a legacy OAuth application with elevated access, to corporate mailboxes.
Rank paths by business impact reached, steps required and detection coverage. The shortest path to a domain admin is not always the most dangerous. The path that reaches backups, the tenant root or payment systems with the fewest detectable steps is.

Why a list of privileged accounts is not enough

Most privileged access programs start with an inventory: who holds Domain Admin, who holds Global Administrator, who has root on production. That inventory is necessary and it is incomplete. It describes where privilege sits. It does not describe how an attacker with no privilege gets there.

An attack path analysis models the second question. It treats identities, groups, roles, applications, hosts and trust relationships as a graph, and asks which sequences of ordinary permissions and exposed credentials lead from a low-value foothold to a high-value outcome. A standard user, a laptop and an unmonitored server can all be steps.

Anatomy of a privileged identity path

Stage	What the attacker needs	Typical bridge	Where it is often missed
1. Foothold	Any valid identity or code execution on one system.	Spray against an account without MFA; phishing; exploited edge device; stolen session.	Test, legacy and service accounts excluded from MFA and monitoring.
2. Credential material	A credential or token with more reach than the foothold.	Cached credentials on a server; directory replication rights; secrets in scripts; synced account hashes.	Servers that hold privileged logons but are not treated as privileged.
3. Control plane reach	A role that changes who can do what.	Sync accounts and servers; delegated reset rights; application permissions; role elevation operations.	Non-human identities and apps that hold powerful roles with no named owner.
4. Impact and persistence	Authority over data, backups and trust.	Federation changes; subscription-level roles; backup and key vault deletion.	Backup and recovery platforms sitting under the same identity plane as production.

Two documented chains

Hybrid pivot to cloud tenant control (Storm-0501)

Microsoft Threat Intelligence described the sequence in public reporting. The actor compromised an Entra Connect Sync server that was not onboarded to Defender for Endpoint and used it as a pivot. It moved laterally, ran a DCSync attack to retrieve password hashes from Active Directory, and then compromised a second sync server tied to a different tenant and domain. Attempts to use privileged accounts failed where MFA was required. So the actor found a different route.

It identified a synced non-human identity that held the Global Administrator role and had no MFA method registered. It reset that account’s on-premises password, which synchronized to the cloud, and registered its own MFA method. A Conditional Access policy required a hybrid-joined device, so the actor moved between systems until it found a hybrid-joined server that satisfied the policy. With Global Administrator access it registered an actor-owned tenant as a trusted federated domain, which allowed it to forge SAML tokens. It then invoked the elevateAccess operation to gain User Access Administrator across all Azure subscriptions and assigned itself Owner.

Three details matter for defenders. The MFA control worked on the accounts it covered, and the path went around it. The Global Administrator was a synced account, so its security depended on the on-premises directory. And the final step was a legitimate cloud operation, not malware.

Application permission path to mailbox access (Midnight Blizzard)

Microsoft reported that the actor used a password spray, with few attempts per account and traffic routed through residential proxies, to compromise a legacy non-production test tenant account that had no MFA. From that account it found a legacy test OAuth application with elevated access to Microsoft’s corporate environment. It created additional malicious OAuth applications and a new user to consent to them, and used the legacy application to grant those applications the Exchange Online full_access_as_app role. The applications then read corporate mail through Exchange Web Services.

This path never touched a privileged human account. The privilege lived in an application nobody was reviewing.

Where privileged paths hide

Directory sync servers and their service accounts. They hold or can reach directory replication rights, and they connect on-premises compromise to cloud control. Microsoft’s recommendations include endpoint protection with tamper protection, TPM on the servers and Conditional Access limits on the directory synchronization account.
Synced administrators. A cloud role held by an account that is mastered on-premises inherits the on-premises attack surface. Microsoft recommends cloud-native accounts for Global Administrators.
Service principals and app registrations. Application-only permissions and powerful roles on apps often survive staff turnover and project closure. Audit unknown, unused and over-scoped identities.
Delegated reset and help desk rights. The right to reset a password or change an MFA method on a privileged account is itself privilege.
Federation and trust configuration. Whoever can change it can mint identities. Treat changes as top-severity events.
Backup and recovery administration. If the same identity plane that runs production also controls backups, a single path ends in both encryption and the loss of recovery.

Building the analysis

Name the end states. Examples: tenant root, domain control, backup deletion, key vault access, payment system administration. These come from business impact, not from the technology.
Collect the edges. Group membership, role assignments, delegated rights, application permissions, local admin rights, logon sessions that expose credentials, and trust relationships, across on-premises and cloud.
Include non-human identities and sync components as first-class nodes. If the graph holds only users and groups, the paths above will not appear.
Compute paths from realistic starting points. Use a standard user, a compromised workstation and an internet-facing server, not only an already-privileged account.
Score and rank. See the table below.
Assign each cut an owner and a validation test. A path is not closed until someone has attempted it again.

Graph tools such as BloodHound can map on-premises directory relationships, and cloud identity platforms expose role and application data through their own interfaces. Neither gives a complete picture alone. The hybrid links are where the data usually has to be joined by hand.

Deciding which paths to cut first

Criterion	Question	Effect on priority
Business impact reached	Does the path end at a crown jewel, recovery capability or the tenant root?	Raises priority sharply
Steps to impact	How many hops from a realistic starting point?	Fewer steps raise priority
Detection coverage	Would any step generate an alert someone acts on?	Silent paths rise
Choke point value	Does one change break many paths?	Highest return per unit of effort
Cost of the cut	Does closing it disrupt operations or integrations?	Sets sequencing, not importance

Choke points repeat. Sync servers, a handful of over-privileged applications and a few delegated rights usually sit under most of the dangerous paths. Fixing those first tends to remove more risk than working through accounts alphabetically.

Cuts that map to the documented chains

Control	Link it breaks	Source
Phishing-resistant MFA for administrators and a registered MFA method on every privileged account	MFA gaps on privileged and non-human admin accounts	Microsoft reporting on Storm-0501
Cloud-native Global Administrators, not synced accounts	On-premises to cloud privilege inheritance	Microsoft reporting on Storm-0501
Protect sync servers like domain controllers: EDR, tamper protection, TPM, limited sign-in sources for the sync account	Hybrid pivot and DCSync from a sync server	Microsoft reporting on Storm-0501
Audit application permissions; remove unused or over-scoped app-only roles and impersonation rights	Application permission path	Microsoft guidance on Midnight Blizzard
Alert on federation and trust changes and on role elevation operations	Persistence through forged tokens and subscription-wide control	Microsoft reporting on Storm-0501
Immutable storage, resource locks and purge protection for backups and key stores	Destruction of recovery after control is gained	Microsoft reporting on Storm-0501
Keep privileged accounts out of day-to-day use and separate administrative from everyday identities	Credential exposure on servers and workstations	MITRE ATT&CK mitigation guidance for Account Manipulation

Proving the cut worked

Re-run the same analysis after each change and confirm the path is gone from the graph. Then test it. A purple team exercise that attempts the original path from the original foothold gives a clear pass or fail and shows whether detection fired. If the attempt succeeds by another route, the graph was missing an edge, and that is useful to know.

Limits of the evidence

Public reporting covers incidents at well-instrumented organizations whose investigators could reconstruct the chain, so the cases shown here are not a random sample. Both chains are Microsoft environments. The principles apply to other identity platforms, but the specific operations and mitigations do not carry over one for one. A path analysis is only as good as its data, and role and permission data go out of date quickly.

Next step

Start with one end state, such as deletion of backups or control of the cloud tenant, and trace backwards to the first low-privilege foothold. The number of hops and the number of silent steps is your starting measure. Cybrilliant can help build and validate this analysis across hybrid environments where internal teams want an independent view of the results.

Sources

Microsoft Threat Intelligence. Storm-0501’s evolving techniques lead to cloud-based ransomware. microsoft.com
The Register. Reporting on Microsoft’s Storm-0501 findings: “The intruder is in the house: Storm-0501 attacked Azure, stole data, demanded payment via Teams.” theregister.com
Microsoft Security Response Center and Microsoft Threat Intelligence. Midnight Blizzard: Guidance for responders on nation-state attack. microsoft.com
MITRE ATT&CK. Account Manipulation (T1098) and its sub-techniques, including mitigations and detection guidance. attack.mitre.org