Embed Size (px)
DESCRIPTION
At all times there have been bad guys, who tried to steal money. ATM machines containing vast amounts of money have always been attractive targets. Until recently, criminals were only using physical weaknesses. Skimmers and shimmers for stealing magstripe-tracking data, fake pin pads and cameras for stealing pin codes, and even fake ATMs were created. Time passed and ATM software started to unify. Where there is unification, there are viruses. Trojan.Skimmer.*, Ploutus and other named or unnamed trojans. And what did we see on the public scene? Vendors started discussing the skimmers problem only after they were detected in the wild. As you remember, Barnaby Jack presented "Jackpotting Automated Teller Machines" at Black Hat USA 2010. He used some vulnerabilities in ATM software. He showed that malware, was injected into the OS of the ATM via bootable flash drive or via remote management TCP port. Barnaby Jack's work was based on assumptions that most vulnerabilities were concentrated in the host machine and that we can and should reuse software made by ATM vendors. And that's quite true, but... antiviruses, locked firmware upgrades, blocked USB connectors, and encrypted hard drives can mitigate such risks. But, what about connecting not to the host machine, but to devices themselves? What countermeasures exist, when we will try to impersonate ourselves as an ATM host? Hacking ATMs with small computer like Raspberry Pi should be impossible, but it isn't. The point of our presentation is to draw attention to the problem, which has existed for quite a long time. The problem is usage of common interfaces (like RS232 or USB) and protocols of communication from host machine to such devices as card readers, pin pads and/or dispenser units.
Citation preview
Hack your ATM with friend's Raspberry.Py
Alexey OsipovOlga Kochetova
Who are we?
• Positive Hack Days Team
• Authors of multiple articles and researches
• White hats
• CLUB-MATE addicts
• Just cool folks
Agenda
• Intro (little bit about ATM history)
• Old physical stuff (Skimmers and pin sniffers)
• Host based attacks (XFS vulnerabilities/insecurities)
• Device-specific attacks
• Demos
INTRO (LITTLE BIT ABOUT ATM HISTORY)
The 1st idea: no ATM – no cry
• 1939 – the 1st idea of ATM
• The City Bank of New York rejected it
• If you don’t have ATM, it can’t be hacked
1967 – the world’s 1st ATM
Card&PIN&online&so on
Today we can use and investigate ATMs
WHY WE ARE DOING IT?
$#it happened
Banks are curious
We are curious
ATMs are hacked• Trojan.Skimers• Backdoor.Ploutus• Tyupkin• Another target attack• Undocumented
features• “Top secret” data is
online
ATM Jackpotting by Barnaby Jack
• Remote controlled ATM with admin tools
• Firmware updates
• Dispense money
OLD PHYSICAL STUFF (SKIMMERS AND PIN SNIFFERS)
• Encrypted PIN Pad
Motorized hybrid card reader
What is inside
•
Motorized hybrid card reader
Card reader
Track2 is enough for transaction
PAN = the 1st part of Track2
• Skimming• Shoulder-surfing, hidden camera, mirrors• Fake PIN pad• Fake ATM
I need your PIN, your card and your cash
Like valid slots
The most popular devices
Converted anti-skimming
3D printing skimming
via http://krebsonsecurity.com/
Fake ATM
Your money is not yours anymore
HOW HARD TO GET INSIDE OF ATM?
- Service zone- Plastic cover
- Single lock
- Safe for money- Steel + concrete
- Rotary code locks/electronic locks
- Two types of locks
ATM countermeasures
How to get in
How to get in
How to get in
ATM is locked
DEMO
HARDWARE AND PREPARATIONS
- Minimal price
- Small
- Capable of using multiple interfaces
Intent
- Raspberry Pi- 2 USB ports- Ethernet
- USB-COM converter- Facedancer (kudos to Travis Goodspeed)- Wifi dongle- Battery =)
Hardware
- PWN Pi
- Python
- pySerial
- pyHID
- pyUSB
- TTWE framework (thx rvantonder)
Software
Raspberry Pi + Python + WiFi = bingo!
Our “malware” devices
HOST BASED ATTACKS (XFS VULNERABILITIES)
XFS insecurity
Network communicationWindows-based application
Configuration information
Unit #1
Service provider #1
Unit #2 Unit #3
Service provider #2 Service provider #3
Unit #4
Service provider #4
Unit #5 Unit #n
Service provider #5 Service provider #n
XFS API
XFS SPI
XFS manager
COM USB
Customer/Service mode
XFS insecurity
Network communicationWindows-based application
Configuration information
Unit #1
Service provider #1
Unit #2 Unit #3
Service provider #2 Service provider #3
Unit #4
Service provider #4
Unit #5 Unit #n
Service provider #5 Service provider #n
XFS API
XFS SPI
XFS manager
COM USB
Customer/Service mode
XFS, PIN Keypad device
PIN device
– Open mode and
secure mode read
data
– Export of key is not
available
XFS, Identification Card Device
IDC device
– Read/write data
– Insert/eject/retain
cards
– EMV reader
Cash Dispenser Device– Cash withdrawal without authorization
– Cassette and cash control
– Software safe opening
XFS, Cash Dispenser Device
- Authentication?
- Hard to get specification?
- Exclusive access to XFS manager/service provider?
XFS authentication
- Authentication? What authentication?
- Hard to get specification? Freely available
- Exclusive access to XFS manager/service provider? Exists, but not intended to be used for security
XFS authentication
• Early 2014 – 95% of ATMs run on Windows XP
• Support killed off in April
• >9000 vulnerabilities
Windows XP still alive
So?
DEMO
DEVICE-SPECIFIC ATTACKS (PHYSICAL INTERFACES COM/USB)
RS232 insecurity
Network communicationWindows-based application
Configuration information
Unit #1
Service provider #1
Unit #2 Unit #3
Service provider #2 Service provider #3
Unit #4
Service provider #4
Unit #5 Unit #n
Service provider #5 Service provider #n
XFS API
XFS SPI
XFS manager
COM USB
Customer/Service mode
DinosauRS232
• Standard interface
• No specific drivers
• No authorization
• Insecure proprietary protocols (just sniff and replay)
• Direct device control– Command execution mitigating all host-based checks,
e.g. cash withdrawal without notes counter checks
– Execution of undocumented functions
– Intercept unmasked sensitive data
• Possibility of producing hardware sniffer, which can’t be detected by software means
Advantages
• Protocols bloat
• Specific method of integrity control
• Short timeouts
• Endless polling
• New firmware version = new protocol
Difficulties
DEVICE-SPECIFIC ATTACKS (COM-PROTOCOLS)
- No good tools for analysis
- No flow control
- No host loss detection
- Packets- Fixed size
- Start/stop bytes
- Length prefix + data
Typical serial protocol
Life without wireshark
Typical data
02 30 XX XX XX
01 0102 00 03 00 04 00 05 00 06 00
10 03 42
Typical serial protocol
02 30 XX XX XX
01 0102 00 03 00 04 00 05 00 06 00
10 03 42
- 02 30 / 10 03 – start-stop sentinels
- XX XX– op-code
- XX – Unknown
- 01 01 … – data
- 42 – CRC8
- Request insert card
- Acknowledge host about card inserted
- Issue 3 separate commands to read 3 tracks
- Issue additional commands for EMV communication
IDC device flow
- Sniff all Track data
- Send to host fake information about inserted card
- Abuse services existent on ATM that don’t involve cash withdrawal
- Card to card transactions
- Payments
IDC device attacks
PIN device flow
- If entering PIN/encryption keys- Authenticate host on currently used keys
- Send empty button press events
- Send PIN block to host
- If entering open string
- Send all button press events with button values to host
PIN device flow
PIN MITM attack
- Request open mode from PIN pad when user is going to insert PIN code
- Acknowledge host about button presses
- Send erroneous PIN block (we don’t know keys)
- Host refuses transaction, but attacker knows client PIN code
- Next transaction will be unmodified
PIN device MITM attacks
- Restart/check device
- Dispense X notes from Y cassettes
- Open shutter
- Present notes to user
Dispenser device flow
DEMO
- No more RS232 – no malicious control
- Any use of cryptography – is equal to good use of cryptography
- We regret informing you that we had decided to stop producing this model and warranties for our distributors been expired (c)
What big vendors think
What we think
HOW TO LIVE WITH ALL THIS?
- Service zone is important
- Current methods of protection is not enough
- Using execution prevention software without OS patches – is wrong
Conclusions
- Implement mutual authentication both for ATM computer and it’s devices
- Make peer review of XFS standard/communication protocols
- Service zone is as important as safe
- Trust environment is not about ATMs
Proposals
Alexander Tlyapov, @Rigmar
SCADAStrangeLove, @scadasl
And all other guys worth mentioning
Kudos
Alexey Osipov, @GiftsUngiven
Olga Kochetova, @_Endless_Quest_
Questions?
