Attack all the layers secure 360

INTRODUCTIONS
Scott Sutherland
 Security Consultant @ NetSPI
 Twitter: @_nullbind
Karl Fosaaen
 Security Consultant @ NetSPI
 Twitter: @kfosaaen
We specialize in both
things and stuff!

OVERVIEW
• Why do companies pen test?
• Attacking passwords
• Attacking protocols
• Attacking applications
• Bypassing AV
• Windows Escalation
• Conclusions

WHY DO COMPANIES PEN TEST?
• Compliance requirements
• Third party requests
• Identify unknown security gaps
• Validate existing security controls
• Prioritize existing security initiatives
• Prevent data breaches

PENETRATION TEST GOALS
• Identify and understand the impact of
vulnerabilities at the application, system, and
network layers
• Prioritize remediation
• Understand ability to detect and respond to
attacks

PENETRATION TEST OBJECTIVES
• *Complete client specific objectives
• Gain access to critical systems, sensitive data, and
application functionality
• Attack Surfaces
Applications
Networks
Servers
• Attack Categories
Configuration issues
Code vulnerabilities
Missing patches

OVERVIEW
• Bypassing AV
• Escalation

ATTACKING PASSWORDS
• Dictionary Attacks
• Dump Hashes and Crack
• Dump Hashes and PTH
• Impersonate
• Dump in Cleartext!

ATTACKING PASSWORDS
1997 2000s 2001 2007 2008 2010 2012

ATTACKING PASSWORDS: DICTIONARY
• Dictionary Attacks
Enumerate users
- Null SMB logins, RPC, *SID BF,
SNMP, LDAP, SharePoint, etc
Attack!
• Are users getting smarter?
Sort of…
- “Spring2013” meets password
complexity requirements

ATTACKING PASSWORDS: CRACKING
• Dumping Hashes and Cracking
John
Rainbow Tables
oclHashcat plus

ATTACKING PASSWORDS: PASSING
• Dumping and Passing Hashes
Pass the hash kit
Metasploit
PTH everything

ATTACKING PASSWORDS: IMPERSONATE
• Impersonate
Incognito
WCE

ATTACKING PASSWORDS: CLEARTEXT
• Dump in Cleartext!
All the applications!
- Egyp7’s script
WCE
Mimikatz

OVERVIEW
• Bypassing AV

ATTACKING PROTOCOLS
• ARP: Address Resolution Protocol
• NBNS: NetBIOS Name Service
• SMB: Server Message Block
• DTP: Dynamic Trunking Protocol
• VTP: VLAN Trunking Protocol
• Honorable Mentions

ATTACKING PROTOCOLS: ARP
Address
Resolution
Protocol

• General
MAC to IP association
Layer 2
• Conditions
Independent of user action
Broadcast network
• Attacks
MITM Monitoring
MITM Injection
DOS

Common ARP MITM attacks:
• Intercept Data
SSN, Credit Cards, Healthcare data, etc
Whole file parsing with NetworkMiner
• Intercept Passwords
Cain will parse passwords for over 30 protocols
• Injection Content
SQL injection – Web and direct database connections
HTML injection – redirection, browser exploits
UNC path injection – Force authentication
Proxy and modify HTTP traffic with Burp Suite

Common ARP MITM tools:
• Windows Tools
 Cain
 Ettercap-ng
 Interceptor-ng
 Nemesis
• Linux Tools
 Ettercap
 Dsniff
 Subterfuge
 Easycreds
 Loki
 Nemesis

Common mitigating controls:
• Dynamic ARP Inspection
• Port Security
• Static Routes (not recommended)

ATTACKING PROTOCOLS: NBNS
NetBIOS Name
Service

• General
 IP to hostname association
 Layer 5 / 7
• Constraints
 Dependent on user action
 Broadcast Network
 Windows Only
• Attacks
 MITM Monitoring
 MITM Injection
 DOS

Common NBNS MITM attacks:
• Intercept Data
Whole file parsing with NetworkMiner
• Injection Content
SQL injection – Web and direct database connections
HTML injection – redirection, browser exploits
UNC path injection – Force authentication
Proxy and modify traffic with Burp Suite

Common NBNS MITM tools:
• Windows Tools
nbnspoof (python)
Metasploit (nbns_response + other modules)
Responder (python)
• Linux Tools
nbnspoof (python)
Metasploit (nbns_response + other modules)
Responder (python)

• Create a WPAD (Web Proxy Auto-Discovery)
server entry in DNS
• Disable NBNS (not highly recommended)
• 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

• 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

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

Many tools support SMB Relay attacks:
• Windows Tools
Metasploit (smb_relay and http_ntlmrelay)
Interceptor-ng
…this is a kind a pain in Windows
• Linux Tools
Metasploit (smb_relay and http_ntlmrelay)
Zack attack
Subterfuge
Squirtle

• Enable packet signing to help prevent SMB Relay
attacks
• Apply really old patches like if you missed out on
the last decade…

ATTACKING PROTOCOLS: DTP
Dynamic
Trunking
Protocol

• 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

• Intercept Data
Whole file parsing with Network Minor

Common DTP spoofing tools:
• Windows Tools
 I got nothing…
• Linux Tools
Yersinia

• 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 8021Q headers
• Configure strong VACLs

ATTACKING PROTOCOLS: VTP
VLAN Trunking
Protocol

• General
802.1Q encapsulation is in use
Layer 2
• Constraints
Independent of user action
VLANs are IP or MAC based
• Attacks
Ability to directly attack
systems on other VLANs

Common next steps after VTP tag forgery:
• MITM attacks against remote VLAN systems
• Intercept/Modify Data
Usually limited to broadcast traffic (unless
MITM)

Tools for VLAN hopping attacks:
• Windows Tools
Native: Manually reconfigure via TCP/IP settings
• Linux Tools
Native: Modprobe + ifconfig
VoIP Hopper
Yersinia

• 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 8021Q headers
• Configure strong VACLs

ATTACKING PROTOCOLS: OTHERS
Honorable Mention:
• Pre-Execution Environment (PXE)
• Link-local Multicast Name Resolution (LLMNR)
• Dynamic Host Configuration Protocol (DHCP)

ATTACKING APPLICATIONS
• Default and weak passwords for everything
 Tools: Nmap, Nessus, Web Scour, Manuals, Google
• SQL injection
 Tools: Manually, web scanners, SQL Ninja, SQL Map, Metasploit
• RFI/Web Shells (JBOSS, Tomcat, etc.)
 Tools: Metasploit, Fuzzdb, and other web shellery
• Web directory traversals
 Tools: Manually, web scanners, Fuzzdb, Metasploit,
• MS08-067
 Tools: Metasploit, exploitdb exploits, etc

BYPASSING AV
• Weak Configurations
• Source Code Tricks
• Binary Modifications
• Process/Thread Manipulation

BYPASSING AV: WEAK CONFIGURATIONS
• Execute from share, UNC path, or external media
• Disable via GUI
• Create policy exceptions
• Kill processes
• Stop / Disable Services
• Uninstall (not recommended)
• Insecure service registration (c:program.exe)
• Insecure file permissions (file replacement/mods)
• Execute from a DLL
• DLL pre loading, side loading etc
• GAC poisoning (potentially)

BYPASSING AV: SOURCE CODE TRICKS
Customize everything…and be crazy
• Migrate to and suspend or kill AV
• Modify comments (web languages)
• Replace variable names
• Modify application logic
• Use alternative functions
• Remove or modify resources
• Encode or encrypt payloads
• Compress payloads
• Add time delays
• Call NTDLL.DLL directly

BYPASSING AV: BINARY MODIFICATIONS
Same idea…be crazy
• Simple string modification
• Decompile/modify source
• Disassemble / modify application logic
• Disassemble /insert time delays
• Modify resource table (ditto/cffexplorer)
• Modify imports table (ditto/cffexplorer)
• Pack (UPX, Mpress, iExpress etc)
• Metasploit Pro Payloads:
dynamic exe generation

BYPASSING AV: PROCESS/THREAD MODS
Inject, inject, replace…
• Code injection (local and remote)
• DLL injection (local and remote)
• Process replacement
Common Tools:
• Powershell: Powersploit, etc
• Python and Py2exe
• Any language that supports
calls to native DLLs

OVERVIEW
• AV evasion

WINDOWS ESCALATION: OVERVIEW
• Local user  Local Administrator
• Domain user Local Administrator
• Local Administrator  LocalSystem
• LocalSystem  Domain User
• Locate Domain Admin Tokens
• LocalSystem  Domain Admin

WINDOWS ESCALATION: LOCAL ADMIN
• Local user  Local Administrator
Excessive local group privileges (admin or power users)
Cleartext credentials
• Sysprep (unattend.xml/ini/txt)
• Config files, scripts, logs, desktop folders
• Tech support calls files
Weak application configurations that allow:
• Restarting or reconfiguring services
• Replacing application files
• DLL pre or side loading
• Executable injection via poorly registered services
C:Program Files (x86) vs “C:Program Files (x86)”
Local and remote exploits (Metasploit: getsystem)

• Domain user  Local Administrator
Issues from last slide and…
Group policy: groups.xml
File shares accessible to domain users
Ability to log into domain workstations
Excessive database privileges (xp_cmdshell etc)
SMB Relay + cracking hashes
Other systems and applications that use integrated
domain authentication…

• Local Administrator  LocalSystem
At.exe (on older systems) – we still see it! 
Accessibility Options
• Replace accessibility options like utilman.exe, osk.exe and
sethc.exe with cmd.exe or other backdoor
Create a custom service to run as LocalSystem
• Psexec –s –i cmd.exe
Migrate to a system process
• Remote process injection, MSF ps + migrate, and
Incognito
Local and remote exploits
• Metasploit: getsystem etc
SQL Server and Database links + xp_cmdshell

WINDOWS ESCALATION: FIND DA TOKENS
• Locate Domain Admin tokens
Check locally ;)
• incognito
Query the domain controllers
• netsess.exe
Scan remote systems for running tasks
• native tasklist or smbexec
Scan old Windows systems for NetBIOS
Shell spraying for tokens (not advised)

WINDOWS ESCALATION: DOMAIN ADMIN
• LocalSystem  Domain Admin
Pass-the-hash to target system
• Local administrator account and shared service accounts
• Manually via trusted connections or via MSF etc
Impersonate authentication token
• Custom application, Incognito, WCE, Metasploit
Dump clear text domain credentials
• Mimikatz, WCE, or Metasploit
Key logging
MITM + sniffing (http integrated auth etc)

CONCLUSIONS
All can kind of be fixed
Most Networks
Kind of broken
Most Protocols
Kind of broken
Most Applications
Kind of broken

ATTACK ALL THE LAYERS!
ANY QUESTIONS?

ATTACK ALL THE LAYERS!
Scott Sutherland
Principal Security Consultant
Twitter: @_nullbind
Karl Fosaaen
Security Consultant
Twitter: @kfosaaen

Attack all the layers secure 360

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