Certified: The GIAC GISF Audio Course

In this episode, we’re going to explore what often happens after an attacker gets an initial foothold, because the first break-in is rarely the end of the story. Beginners sometimes picture an attack as a single successful login or a single malicious file, followed immediately by stolen data. In real intrusions, attackers usually need to increase their control and broaden their access before they can reach the systems or data they truly want. Two of the most common ways they do that are privilege escalation and credential theft. Privilege escalation is about gaining more power than you started with, and credential theft is about stealing the keys that let you move around like a legitimate user. These are core post-exploitation techniques because they help attackers turn a small entry point into a larger, more damaging compromise. Our goal is to learn how to recognize these ideas conceptually and understand the kinds of clues they tend to leave behind.

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.

Let’s define privilege escalation first, because the term can sound more mysterious than it is. Privilege is simply the level of access or authority an account or process has. A normal user might be allowed to read their own files and use basic applications, while an administrator might be allowed to install software, change security settings, and access sensitive system areas. Privilege escalation happens when an attacker increases their authority beyond what they legitimately have. This can happen in two broad ways. One is vertical escalation, where a low-privilege account becomes a high-privilege account, like a regular user becoming an administrator. The other is horizontal escalation, where the attacker gains access to another account at the same general level but with access to different resources, like switching from one user to another user who can access a specific folder. Both forms matter because they expand what the attacker can reach, and both can be stepping stones toward full control of a system or environment.

A key concept for beginners is that privilege escalation is often about bypassing boundaries that were meant to protect sensitive operations. Those boundaries might be operating system permissions, application role assignments, or security controls that require approval for certain actions. Attackers look for weaknesses in those boundaries. Sometimes the weakness is a software vulnerability that allows a process to run with higher privileges than intended. Sometimes the weakness is a configuration mistake, such as a service running with excessive permissions. Sometimes the weakness is simply that a user already has more privileges than they need, which gives the attacker a shortcut. This is why the principle of least privilege matters. If accounts and services only have the minimum permissions required, then an attacker who compromises one account has a harder time escalating. Privilege escalation is not just an attacker skill; it is also a reflection of how well access boundaries were designed and maintained.

Now let’s define credential theft and why it is so powerful. A credential is anything that proves identity or grants access, such as a password, a cryptographic key, a session token, or an authentication cookie. Credential theft is the act of acquiring those secrets so the attacker can impersonate users or systems. On first mention, you will often hear the term credential dumping, which is a technique where an attacker attempts to extract stored credentials or credential material from a system. Once credentials are stolen, the attacker can often avoid noisy exploitation techniques and instead move through the environment using legitimate authentication pathways. This is sometimes described as using the front door with stolen keys. Credential theft is especially dangerous because it can allow persistence. Even if you remove a malicious program from one device, stolen credentials may still allow the attacker to log in again from somewhere else.

A beginner-friendly way to connect privilege escalation and credential theft is to see them as partners. Attackers often steal credentials to gain new access, and they often seek higher privileges to steal more valuable credentials. For example, a low-privilege foothold may allow an attacker to observe a user entering a password or to capture a session token. With that access, they may reach another system where higher privileges are available. Once they gain administrative privileges, they may be able to access credential stores, memory areas, or configuration files that contain additional secrets. This creates a snowball effect where access grows over time. That is why defenders focus so heavily on interrupting these steps. Stopping an attacker early is ideal, but if you miss the initial entry, identifying credential theft and privilege escalation quickly can still prevent the attacker from achieving their ultimate objective.

To recognize these techniques, it helps to think about what changes when privileges increase. A process that previously could not modify system settings suddenly can. An account that previously had limited access suddenly performs administrative actions. A device that previously only ran user-level programs suddenly spawns system-level processes in unusual ways. These are conceptual signals, not tool-specific details. For example, an unusual attempt to add an account to an administrative group is a strong indicator that privilege escalation is being attempted or has occurred. Another example is a pattern of access requests that suddenly shifts from normal user activity to system configuration changes. The details vary across systems, but the theme is consistent: privilege escalation causes a change in the types of actions that become possible, and those actions often stand out when compared to typical behavior.

Credential theft also leaves conceptual clues, and one of the most important is unusual authentication behavior. If an account begins authenticating from new locations, at unusual times, or to systems it never touched before, that can indicate that the credentials have been stolen and are being used elsewhere. Another clue is the sudden appearance of authentication attempts across many systems, especially if the attacker is trying multiple passwords or probing for where the stolen credential works. Credential theft can also be indicated by unusual access to credential-related resources, such as reading sensitive configuration areas, accessing secure storage locations, or interacting with authentication services in unexpected ways. Again, the point is not to memorize every possible sign. The point is to recognize that credential theft has a purpose: to enable impersonation and movement. That purpose creates patterns that can be detected through thoughtful monitoring.

A common misconception is that credential theft always means the attacker has captured a plain-text password, but many modern attacks rely on token theft or session hijacking. A session token is a piece of data that proves you already authenticated, allowing you to continue accessing a service without re-entering your password every time. If an attacker steals a token, they may be able to act as the user without knowing the password. This is particularly relevant in environments where single sign-on is used and where sessions persist for a long time. Another misconception is that multi-factor authentication makes credential theft irrelevant. Multi-factor authentication helps significantly, but it does not eliminate risk. Attackers may steal tokens after authentication, use social engineering to trick users into approving prompts, or find paths that bypass multi-factor on certain legacy systems. The beginner takeaway is to treat credentials broadly, not just as passwords, and to understand that attackers adapt to the authentication methods in place.

Privilege escalation is also often misunderstood as purely a technical hack, like exploiting a software bug. While vulnerabilities are one path, privilege escalation frequently occurs through misuse of permissions and trust relationships. If a user is already a local administrator on their machine, the attacker who compromises that user account may not need to escalate much at all. If a service account has access to multiple systems and uses the same credentials broadly, stealing that one credential can act like privilege escalation across the environment. Even within applications, role-based access controls can be misconfigured so that users have excessive roles. These are not flashy exploits, but they produce the same outcome: the attacker can do more than they should. That is why governance and access management matter even for beginner-level security understanding. The attack does not care whether the path was clever or simple. It cares only that it works.

Defenders often detect these techniques by watching for certain categories of behavior rather than single indicators. For privilege escalation, that includes changes to groups and roles, creation of new accounts, changes to security policies, and unusual administrative tool usage. For credential theft, that includes access to credential storage areas, unusual process behaviors tied to authentication mechanisms, and suspicious authentication patterns across systems. In a modern stack, E D R might provide visibility into local process behaviors and suspicious access to sensitive memory areas, while identity logs might show unusual login patterns. A SIM can correlate these signals to form a stronger narrative. For instance, a suspicious process behavior on an endpoint combined with an unusual login pattern for the same user account creates higher confidence than either alone. This layered approach matters because attackers often try to keep each individual action subtle. Correlation is how subtle actions become a visible story.

It is also useful to understand what attackers often do right after achieving privilege escalation or credential theft, because that helps you anticipate next steps. Once an attacker has higher privileges, they may attempt to disable security controls, create persistence mechanisms, or expand access by adding accounts and permissions. Once an attacker has stolen credentials, they may attempt lateral movement, accessing other systems to find data or additional privileged accounts. They may also attempt to access email or collaboration platforms, because those often contain sensitive information and can be used for further social engineering. Recognizing this sequence helps you prioritize investigation. If you suspect credential theft, you focus on where those credentials could be used next. If you suspect privilege escalation, you focus on what high-impact actions become possible and whether any defenses have been weakened.

By the end of this lesson, you should be able to explain privilege escalation as the act of increasing authority and credential theft as the act of stealing access secrets, and you should understand why these techniques often appear together during post-exploitation. You should also be able to reason about conceptual clues, such as sudden administrative actions, unexpected role changes, unusual authentication behavior, and access to credential-related resources. The point is not to become a forensic specialist. The point is to build a clear, beginner-friendly mental model of how attackers grow their power after getting in, and how defenders notice the patterns that growth creates. The decision rule to remember is this: when you see evidence of a foothold, immediately ask whether the next likely move is privilege escalation or credential theft, and then look for behavioral signals of increased authority or unusual authentication that confirm or refute that suspicion.