Transcript Rootkits
Students: Jacek Czeszewski and Marcos Verdini Rosa Professor: José Manuel Magalhães Cruz o Introduction o How a rootkit works o Detection o Preventing and Removing o Attack damage o References A rootkit is a suite of one or more programs that allows a third party to hide files and activities from the administrator of a computer system. The original intent of rootkits (1996) appears to have centered simply on hiding programs that would allow an attacker to “sniff” or spy on traffic going to and from a computer system. Provide an attacker with full access via a backdoor, permitting unauthorized access to, for example, steal or falsify documents. Conceal other malware, notably password-stealing key loggers and computer viruses. Appropriate the compromised machine as a zombie computer for attacks on other computers. Enforcement of digital rights management (DRM). Conceal cheating in online games. Detect attacks, for example, in a honeypot. Enhance emulation software and security software. Anti-theft protection. Bypassing Microsoft Product Activation User mode Kernel mode Bootkits Hypervisor level Hardware/Firmware run in Ring 3 many installation vectors Make to execute inside any target process or overwrite the memory of a target application run in Ring 0 adding code or replacing portions of the core operating system, including both the kernel and associated device drivers unrestricted security access lows the malicious program to be executed before the operating system boots cannot be detected by standard means of an operating system because all its components reside outside of the standard file systemserating system boots uses hardware virtualization trap a running instance of the operating system by starting a thin hypervisor and virtualizing the rest of the machine under it dont have to load before the OS hidden in BIOS, network card etc. only way to remove is to replace infected hardware could be hidden outside the computer for example in network printer • • • • • Installation Physical access to the target system Privilege Escalation Cloaking Obscure its presence from security tools Modify the behavior of OS core parts Load code into other processes Stoned is the name of a boot sector computer virus created in 1987, apparently in New Zealand. It was one of the very first viruses. A memory resident bootkit up to the Windows kernel Boot applications executed on startup Drivers executed beside the Windows kernel Your PC is now Stoned! (1987) Your PC is now Stoned! ..again (2010) Windows Boot Process Windows boot system assumes an already secure environment when starting Hooking and Patching Interrupt 13h hooked Ntldr hooked for calling 32bit code and patching the code integrity verification Patching the NT kernel Executing pay loads(driver) Installation Live CD Infected PDF Demonstration Signature-Based File Integrity Monitoring Cross-View Analysis Hooking Detection Heuristics-Based Detection Network-Based Detection 3.1 Signature-Based Detection • • • analyzing rootkit to define fingerprint integrating fingerprint in to the database fingerprint can be used for rootkits detection 3.2 File Integrity Monitoring • calculates cryptographic hashes for critical, unchanging operating system files and compares them to known values that are stored in a database 3.3 Cross-View Analysis • It involves looking at the system from the high level “user”, or API view, and comparing it to the actual low level hardware view. 3.4 Hooking Detection • When the rootkit modifies a hook to point to a malicious service or interrupt routine, the memory location almost invariably is located outside this specific range of the “clean” system, and is easily detected. 3.5 Heuristics-Based Detection • Heuristics-Based detection of malware attempts to classify malicious behavior according to certain pre-determined rules. 3.6 Network-Based Detection • • System periodically send a snapshot of the network traffic and open ports to a trusted gateway for analysis. The gateway compare this data with its “external” view of the system’s network activity Operating system updates Automatic updates Personal firewalls Host-based intrusion prevention systems Rootkit prevention techniques number of security-software vendors offer tools to automatically detect and remove some rootkits Some antivirus scanners can bypass file system APIs, which are vulnerable to manipulation by a rootkit There are experts who believe that the only reliable way to remove them is to re-install the operating system from trusted media in some cases the only possibility is to replace some hardware Home Users Stealing Identity and private information Turning Home User's computers into zombies Loss of time, money and confidence Enterprise and Government • Loss of confidential information, theft of intellectual property Reputation and customer trust Additional costs of purchasing, installing, and administering security measures Increases system complexity Stallings & Brown - Computer Security: Principles and Practice A comparative analysis of rootkit detection techniques by Thomas Martin Arnold Ric Vieler - Professional Rootkits http://en.wikipedia.org/wiki/Rootkit http://opensecuritytraining.info/Rootkits.html http://www.stoned-vienna.com