Certified: The GIAC GCLD Audio Course

In this episode, we focus on initial access, because most cloud incidents become expensive and embarrassing only after an attacker gets a foothold and starts acting like they belong. If you can identify the entry paths that are most common in public cloud environments, you can close doors early and force attackers into slower, noisier methods. That is the real payoff of studying initial access. You are not trying to predict every possible exploit; you are trying to remove the easy wins that automated campaigns and opportunistic attackers depend on. For exam performance, this topic is usually tested through scenarios that ask what went wrong first, what control would have prevented the first step, or what evidence would confirm an entry path. When you know the common doors attackers use, you can also be calmer during investigation, because you have a short list of likely routes rather than an endless fog of possibilities.

Before we continue, a quick note: this audio course is a companion to our course companion books. The first book is about the exam and provides detailed information on how to pass it best. The second book is a Kindle-only eBook that contains 1,000 flashcards that can be used on your mobile device or Kindle. Check them both out at Cyber Author dot me, in the Bare Metal Study Guides Series.

A good starting point is exposed services and forgotten internet endpoints, because cloud makes it easy to create public reachability without fully realizing the consequences. Teams spin up test environments, temporary admin interfaces, and short-lived proofs of concept, and those assets often outlive the project that created them. An exposed endpoint might be a web service, a management console, a remote administration port, or an API that was meant to be internal but was deployed with public access for convenience. Attackers do not need creativity here. They scan for what is reachable, fingerprint what it is, and probe for weak authentication and known weaknesses. Forgotten endpoints are especially attractive because they often have weaker monitoring and less disciplined patching. The defensive implication is that exposure is not a one-time decision. Public reachability is a property that must be continuously discovered, validated, and justified, because drift happens naturally as environments change.

Alongside exposure, stolen credentials remain one of the most reliable initial access methods in cloud. Credentials are stolen through phishing, malware, and simple credential reuse from unrelated breaches, and cloud identities are valuable because they can unlock broad access quickly. Phishing works because humans are busy and attackers are good at creating urgency. Malware works because a compromised workstation can steal browser sessions, tokens, and saved credentials without needing to break cloud services directly. Credential reuse works because many people reuse passwords and because credential stuffing can be automated at scale. Once an attacker has a valid identity, they can blend in with normal activity unless monitoring is strong. This is why identity is not just an authentication problem. It is a detection, governance, and privilege design problem, because the impact of stolen credentials depends on what those credentials can do and how quickly you can notice misuse.

A special and painfully common version of credential exposure is leaked access keys, especially in environments where developers move quickly. Access keys end up in code repositories, ticketing systems, chat logs, or shared documents because people prioritize getting things working over keeping secrets contained. Sometimes the leak is accidental, such as a commit that includes a configuration file. Sometimes it is a workflow issue, such as pasting a key into a ticket to help someone debug. Sometimes it is an integration choice where keys are hardcoded in scripts and then copied across environments. Attackers actively search public repositories and other exposed sources for keys, because it is low cost and high payoff. The defensive lesson is that keys should be treated like cash. You minimize where they exist, you rotate them, you scope them tightly, and you monitor for their use. Even when the key is technically valid, it can become a compromised entry path the moment it is exposed outside its intended boundary.

Misconfigured storage sharing is another initial access path that can cause immediate damage even without a traditional compromise. In cloud, storage services often support sharing models that can accidentally allow anonymous access or overly broad access across accounts and tenants. A dataset meant for internal use might be exposed publicly because of permissive policies, inherited permissions, or a misunderstanding of default settings. Attackers do not always need to break in if the data is already reachable. They can simply enumerate and download. Even when the storage is not fully public, overly broad access within an organization can allow an attacker who compromises a low-privilege identity to reach sensitive data quickly. The defensive implication is that data exposure can be an entry path, not just an outcome. If the first sign of compromise is that data was accessed externally without authentication, the root cause may be a policy misconfiguration rather than a stolen account. Fixing that requires both preventive guardrails and continuous validation of access settings.

Vulnerable web applications running on cloud compute remain a classic entry method, and cloud does not change the fundamentals of that risk. A web application can be vulnerable due to unpatched dependencies, insecure input handling, weak authentication logic, or unsafe default configurations. When such an application is exposed publicly, attackers can probe it and exploit it using well-understood patterns. The cloud twist is that a compromised web app often has an attached identity, such as a workload role or service account, that grants access to other cloud resources. This means a simple web flaw can become a pivot into storage, messaging systems, secrets, or administrative APIs, depending on how privileges were assigned. Attackers love this because they can turn an application-level weakness into cloud-level reach. The defensive lesson is to treat application security and cloud identity design as one system. Strong isolation and least privilege can prevent a web compromise from becoming an environment compromise.

Supply chain compromise adds another dimension, because an attacker may enter through the tools and dependencies used to build and deploy cloud workloads. Build tools, pipeline runners, dependency packages, and container images can all become carriers for malicious changes. In modern delivery workflows, the build system is a high-value target because it can touch many environments and deploy changes automatically. Attackers may compromise a dependency, poison an artifact, or gain access to the pipeline itself and then insert backdoors into what appears to be a normal release. The initial access here is not a login to the cloud console in the traditional sense. It is the ability to influence what gets built and deployed. The defense is therefore not only about perimeter restrictions. It is about controlling build permissions, protecting secrets used in pipelines, verifying the integrity of artifacts, and monitoring for unusual changes in build and deployment behavior. For exam thinking, supply chain initial access often appears as a scenario where a trusted process is abused rather than an obvious external attack.

Third-party integrations are also a common entry path, especially when they rely on delegated permissions that are broader than necessary. Organizations connect cloud environments to software services for monitoring, ticketing, automation, backups, and productivity. These integrations often require permissions to read data, manage resources, or operate across multiple accounts. If the delegated permissions are overly broad, the integration becomes a powerful identity that can be abused if the third party is compromised or if the integration credentials are exposed. The attacker’s initial access might occur in the third party, but the effect is access into your environment through an approved channel. This is why integration design must be threat-aware. You should scope permissions, segment access, enforce strong authentication for administrative actions, and continuously review what the integration can do. The key idea is that trusted connections are not free. They are controlled risk, and controlled risk requires ongoing governance.

To make the topic practical, practice mapping one entry path to the controls that reduce it, detect it, and contain it. Pick a single path, such as leaked access keys, and trace what would prevent it and what would expose it if it happens anyway. Prevention might include minimizing key use, using short-lived tokens, and keeping secrets out of code and collaboration tools. Detection might include alerts on key usage from unusual locations, unusual access patterns, or sudden privilege changes associated with that identity. Containment might include rapid revocation, forced rotation, and restricting what the key can access so the blast radius is limited even before you respond. If you choose exposed endpoints as the path, prevention includes limiting public reachability and strong access controls, detection includes monitoring for probing and failed authentication patterns, and containment includes isolating affected services and tightening network rules. This exercise teaches you to see initial access as a controllable risk with specific levers, not as a mysterious event that only incident responders can understand.

A major pitfall in cloud security is assuming perimeter tools cover cloud identities the same way they did in traditional networks. In many environments, classic perimeter thinking focuses on network chokepoints, but cloud identities can be abused without ever crossing those chokepoints in the way you expect. An attacker can authenticate to cloud services directly over normal provider APIs, and that traffic may look like ordinary service usage unless you have identity-aware monitoring. This is why a strong external firewall does not replace strong identity governance. If credentials are stolen, the attacker may be inside the control plane, issuing legitimate API calls that bypass assumptions about where security inspection happens. The defensive response is to treat identity events and cloud API activity as first-class telemetry. You want to know who is doing what, from where, with what privileges, and whether that behavior matches expected patterns.

A quick win that reduces exposure risk immediately is inventorying public exposure weekly. The emphasis is on weekly because exposure changes. New endpoints appear, old ones linger, and temporary exceptions become permanent. A weekly rhythm creates a habit of catching drift before it becomes normal. This inventory should identify what is publicly reachable, what should be public, and what controls surround public assets. It should also include administrative interfaces and sensitive services that should never be exposed broadly. When you run this check consistently, you reduce the number of surprise entry paths attackers can find with automated scans. Even if you do nothing else that week, reducing public exposure is one of the highest leverage moves in cloud defense because it shrinks the attack surface and removes easy targets.

Now rehearse a scenario responding to a suspicious new login, because identity-driven initial access is so common. Imagine you see a login to a privileged account that does not fit normal patterns, such as unusual time, unusual source, or an unexpected device context. Your first move is to contain risk without assuming the full story. You confirm whether the login is legitimate through established verification channels, and you assess what the identity could do if it is compromised. Then you look for follow-on behavior that indicates attacker intent, such as enumeration of resources, role changes, creation of new credentials, or high-volume data access. You also check whether the login was preceded by password reset activity, unusual authentication failures, or other signals of credential abuse. The goal is to interrupt the attacker’s sequence early. If the initial access was real, every minute matters, and a calm, evidence-driven response prevents both overreaction and delay.

To keep all of this memorable, use a simple memory anchor: doors, keys, and guest passes. Doors represent exposed endpoints and services that are reachable from the internet. Keys represent credentials and access keys that can be stolen, leaked, or reused. Guest passes represent delegated access through third-party integrations and trusted relationships that can be abused. When you find a cloud incident, you can ask which category is most plausible and then focus your investigation. If the evidence points to a door, you look at exposure inventory, ingress logs, and application vulnerabilities. If it points to a key, you look at authentication events, token usage, secret exposure, and privilege scope. If it points to a guest pass, you look at integrations, delegated permissions, and unusual activity from service identities. This anchor is simple, but it is effective because it narrows your search space quickly under pressure.

As a mini-review, keep the entry paths organized as a small set of repeatable patterns. Exposed services and forgotten endpoints are common because cloud makes public reachability easy and drift is normal. Stolen credentials from phishing, malware, and reuse provide a powerful and often stealthy foothold. Leaked access keys in code, tickets, and chats are a frequent self-inflicted wound that attackers actively hunt. Misconfigured storage sharing can expose data directly and can also widen blast radius after a compromise. Vulnerable web applications on cloud compute remain a classic entry path, often amplified by attached workload identities. Supply chain compromise enters through build tools and dependencies, abusing trusted delivery mechanisms. Third-party integrations with overly broad delegated permissions create guest passes that can be abused if compromised. The pitfalls include overreliance on perimeter tooling for identity threats, while quick wins like weekly exposure inventory shrink attack surface rapidly. Scenario rehearsal for suspicious logins builds operational readiness and reinforces that early containment and evidence gathering matter.

To conclude, initial access in public cloud is rarely mysterious when you know where to look. Attackers favor doors that are exposed, keys that are stolen or leaked, and guest passes created through trusted integrations, because those paths are scalable and often difficult to distinguish from legitimate activity. Your defenses should therefore focus on reducing public exposure, strengthening identity governance, protecting secrets, hardening internet-facing applications, and treating build pipelines and integrations as security-critical assets. When a suspicious login appears, a calm, evidence-driven response can interrupt the sequence before persistence and data theft occur. List your top five entry paths today.