In this lesson,
we will learn about Memory-based Attacks.
Memory-based attacks exploit vulnerabilities
in a system's memory management to execute malicious code,
manipulate data, or cause system crashes.
Memory-based attacks include attacker tactics,
techniques and procedures or TTPs specific to memory
and shimming.
These attacks often target
the way a program allocates and manages memory,
taking advantage of vulnerabilities like buffer overflows
to inject or execute harmful code.
Shimming works by placing a malicious layer of code
that intercepts communication between the application
and the operating system, allowing the attacker
to modify inputs, outputs, or system calls.
Let's learn more about memory and shimming attacks.
First, we have memory attacks.
Memory attacks are a type of malicious activity
that targets a system's memory management
to exploit vulnerabilities and execute harmful code.
These attacks often manipulate how memory is allocated
and accessed in programs,
taking advantage of programming flaws like buffer overflows
or null pointer dereferences.
When attackers exploit these vulnerabilities,
they can inject malicious code, manipulate data in memory,
or crash the system entirely.
Memory attacks are particularly effective
because they leverage the system's own memory processes
making it difficult for standard security software
to detect them until after the attack is in progress.
For example, a common memory attack is the buffer overflow,
where an attacker deliberately inputs data
that exceeds a buffer's capacity,
overriding adjacent memory locations.
In doing so, the attacker can replace
legitimate code in memory
with their own malicious instructions.
If successful, the system will execute the attacker's code
with the same permissions as the vulnerable application,
which could allow for activities
like unauthorized data access or command execution.
Next, a null pointer dereference occurs
when an attacker attempts to access or modify data
through a pointer that has a null or a zero value.
In programming, a pointer is a variable
that holds the memory address of another variable,
allowing the program to access a location.
A null pointer, however, points to no valid memory location.
So when a program tries to dereference a null pointer,
meaning when it attempts to read or write data
at that null address, this can lead to a crash
or abnormal termination
because the system doesn't allow access
to this invalid memory area.
Null pointer dereferences
may also create security vulnerabilities.
For example, if an attacker can control inputs
to the program,
they might trigger a null pointer dereference
causing a denial of service by crashing the application.
In certain cases, null pointer dereferences
can also be combined with other vulnerabilities
to escalate privileges or execute unauthorized code.
So to mitigate memory-based attacks,
developers should employ secure coding practices
like input validation and bounds checking,
which help prevent buffer overflows
and other input vulnerabilities.
Using languages or libraries
with built-in memory safety features
can also reduce the likelihood of errors
that attackers could exploit.
Finally, implementing security mechanisms
such as Address Space Layout Randomization
and Data Execution Prevention make it more challenging
for attackers to predict memory addresses
and execute unauthorized code in protected regions,
providing an additional layer of defense
against memory related exploits.
Second, we have shimming attacks.
Shimming attacks involve placing a malicious shim
or layer of code between an application
and the operating system
to intercept and manipulate system calls.
By doing so, the attacker gains control
over the inputs and outputs between the software
and the system, potentially modifying data
or redirecting commands to achieve unauthorized actions.
Shims are often used in attacks
that require persistence and stealth
as they allow attackers to inject or alter code
in a way that bypasses traditional detection methods.
Shimming is especially dangerous
because it operates at a low level
below standard applications,
making it challenging for antivirus programs
and security software to detect.
An example of a shimming attack is an attacker targeting
a vulnerable application to inject a malicious shim
that intercepts system calls related to user authentication.
This shim, which is essentially a small piece of code
that intercepts and modifies interactions
between an application and the underlying operating system,
often by manipulating system calls
or application programming interface functions
could intercept login credentials or system commands,
redirecting them to an attacker's server
or enabling unauthorized access to secure data.
Attackers could use methods
like application programming interface hooking
or reflective dynamic link library injection
to place the shim, allowing them to manipulate data flows,
capture passwords,
or escalate privileges from a standard user
to an administrator without being noticed.
So to prevent shimming attacks,
organizations should deploy code integrity practices
that verify only trusted signed code
is allowed to load on a system.
Additionally, implementing application allow listing
and using secure boot can also help ensure
that only verified applications
interact with system processes.
Next, regularly updating and patching software
can protect systems as updates often address security flaws
that could be exploited by shimming techniques.
Finally, using monitoring tools
like endpoint detection and response
and security information and event management
or SIM platforms
that detect unusual activity in system calls
or user privileges can help identify and mitigate
shimming attacks early.
So remember, memory-based attacks target weaknesses
in how a system manages its memory,
allowing attackers to execute malicious code,
manipulate data, or crash applications.
These attacks often exploit flaws
in memory allocation or management,
such as buffer overflows
to insert harmful code into an IT system.
Shimming attacks, also a type of memory-based attack,
involves placing a layer of malicious code
between an application and the operating system
intercepting and altering system calls
to achieve unauthorized access or actions.
Both types of attacks are dangerous
because they operate within the system's own processes,
making them difficult
for traditional security tools to detect.
So to prevent these vulnerabilities,
secure coding practices, regular software updates
and monitoring tools should be used
to detect and mitigate suspicious activity
at the memory and system level.