So you’ve been hacked… now what€¦ · • Anything you do leaves its own traces • Work on copies of the snapshots • You can restart from fresh copies anytime • There maybe

Frédéric G. MARAND http://www.osinet.fr/

So you’ve been hacked…now what ?

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©2018 OSInet - Licensed under Creative Commons CC-BY-SA 4.0

Table of Contents

1 Intro : setting the stage 2 Snapshotting 3 Maintaining presence 4 Crisis communication 5 Rebuild, don’t repair 6 Using forensics tools 7 Back online

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1.1 Some fact checking first

• In this room … • Whose site has been hacked already ?

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• In this room … • Whose site has been hacked already ? • Who feels ready to face a hacked server ?

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• In this room … • Whose site has been hacked already ? • Who feels ready to face a hacked server ? • Who actually has a business continuity plan ?

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• In this room … • Whose site has been hacked already ? • Who feels ready to face a hacked server ? • Who actually has a business continuity plan ? • Who actually has a GDPR-compliant business continuity plan ?

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• In this room … • Whose site has been hacked already ? • Who feels ready to face a hacked server ? • Who actually has a business continuity plan ? • Who actually has a GDPR-compliant business continuity plan ? • Who read node 2365547 ?

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©2018 OSInet - Licensed under Creative Commons CC-BY-SA 4.0 8


1.2 Can you say that again ?

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I.A.N.A.L. (and you probably ain’t either)

So be sure to get one !


1.3 Whence do I speak ?

• Drupal org member since 2005 (fgm) • Drupal consultant, not a site building agency • Worked on fixing broken(-in) sites since 2008 • Auditing • Fixing technical flaws • Addressing intrusions / exploits

• Mostly Media and Government sites (.fr) • « Provisional member » on the Security Team

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1.4 Choose your own adventure

• 10:00 The daily scrum has just begun. • 10:01 Phones rings : someone noticed your site has been defaced and

is warning you • 10:02 Twitter and Reddit start buzzing • 10:05 Phones ring all over the place, journalists and CxO types on the

other end, asking about GDPR Art. 33/34 ; your mailbox is filling with warnings • What is your next step ?

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1.5 Get ready

• Notepad 1 : discovery log • all your work steps, to the

tiniest • all your findings /

observations • with timestamps and

numbers

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• Notepad 2 : remedies ideas • all your ideas for fixing

the breach • all your ideas for further

hardening • cross-refer notepad 1

numbers


2.1 Forensic copy : why ?

• Obvious temptation: • restore & resume • Still vulnerable • So you need to diagnose

• Analyzing means modifying • So preserve the « crime scene » • Snapshot everything

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2.2 Snapshots : pull the plug ?

• Prevents interference • Shutdown handlers, SIGPWR • Self-destructing code on

network loss • Easy on VMs, cloud instances • No need to pull the plug

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• But… • Bare remote servers • Further data loss • Journaled FS • Databases

• Service interruption


2.3 Snapshots : everything == ?

• Not just the main DB

• Reverse Proxy logs • Web fronts • DB servers • File servers

• Also…

• External logs (SaaS) • External transactions • FW/IDS/WAF logs

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The site might be just another attack vector, not the main target


3.1 Maintaining presence #1

• Pros • Don’t tip off hackers: you’re

one step ahead until they notice • Keep on generating short-

term value

• Cons • Damage increase • Responsibility • Legal (GDPR) • Financial • Moral

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As though intrusion had not been detected


3.2 Attacker workflows (intermezzo)

Modern: multistep flow

• Break in

• Dig for gold • Implant zombie

• Wait for implant migration to archives

• Activate • Profit

Amateur: Need for Speed

• Use exploit ASAP

• While it lasts • Usually least loss (miners)

Art crime: hide the act

• Valuable content

• Identity data • Close the door

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(➡ forensics)(➡ restore)



• Limited static site • Best with prior work • Minimal subset • Possibly taken from RP cache

• Very little load • Can run off RP heads

• Working limited (read-only) site • Alternate infra • Alternate tech

• Updates ? • Content created during

crisis

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Safe fallback mode

Always easier if planned from the onset. Can help with GDPR Art 41.2b



• Social networks and status sites • Always there • Also authoritative for audience

• Still needs some preparation • Accounts access • Inclusion in long-term communication

• B2C: Facebook / Instagram pages • B2B: Twitter, status sites

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When all else fails

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4.1 Communicating : upstream

• Internal stakeholders • DPO if any personal data are involved • CxO level in most cases

• Gag orders ? Protection may exist. But follow the rules. • France: whistleblower protection in Sapin 2 (limited) • Italy (banks): Dec. 385 01/09/93 sect 52bis • US (contractors): Anti-SLAPP • Many countries have similar rules

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4.2 : Communication : C-level

• DPO (start here), Legal counsel • Crisis Management specialists (costs…)

• Law enforcement • National data protection agencies within 72h (GDPR Art. 33, Rec. 85) • EU countries typically have« cybercrime » units like (FR) ANSSI

• Other sites • On same server • On same network • Online business partners ➡ GDPR: Data Processors or 3rd parties ?

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4.3 Communication : privacy

• Often personal data leaks • will happen, or... • unprovable they did not

• Operational constraints • Commerce : PCI/DSS

(12 steps etc) • Health : (US) HIPAA

Subtitle D E2.80.93 • Public image damage control

• GDPR Conflicting rules • 72h delay for sensitive

exploits (Art. 33.1), or justification needed • Police operations need time.

Per GDPR, police prevails (Rec. 86)

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5.1 Rebuild : keep, rollback or ..?

• Restore and restart same ? • Still just as vulnerable, just

more so • Keep and fix ? • lots of time and effort

reviewing • never completely trusted : not

just Drupal

• Throw away ? • Event sites, past lines of biz,

post-M&A... • Can a static version suffice ? • From RP snapshots : recent

content • Best: rebuild from sources +

restore backups

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5.2 Rebuild : restore content

• Needs backups from before the hack • Do you know when it happened ? Hint: « modern workflow » • GFS, continuous incremental, 15 min ? • How much can you lose ?

• FLOSS solutions : Amanda, Bacula, custom… • Unprepared emergency ? • Preproduction, CI builds…

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(➡ modern workflow)


5.3 Rebuild : sources + export

• Easy and reliable, but assumes : • Code-driven development process • Reliable data export system in place • Accessible content exports (e.g. flat files, journals) • Content + assets repositories

• Still need to add the fixes • Delay can be a problem on high-volume sites • Bulk handling, Incremental loading

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5.4 Rebuild : other cases

• Ad hoc « traditional » build process • Longer, less reliable • Too long to be a chance to fix the process

• From scratch • Too long in most (all ?) cases • Do it as a complement after the fix • Not NOW

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6 Forensics : switching hats

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6.1 Forensics : first, think !• How did you discover the hack ? • What did it take to succeed ? • Cast your net wide, think big • « Unlikely » vs « impossible »

• Priority : • Easiest attacks first • OWASP 10 • GIYF : search for notepad 1

patterns

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« Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth. » Arthur Conan Doyle «The sign of the four »


• /anything/ may be erased after success • But most of the time, not /everything/ will

• Anything you do leaves its own traces • Work on copies of the snapshots • You can restart from fresh copies anytime

• There maybe more than one exploit • « Cleaner exploits » after Drupalgeddon 1 • « art crime » workflow

6.2 Forensics : keep in mind

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(➡art crime)


6.3 Forensics : classic flaws

• Code files : • lax permissions • filesystem traversal issues • Remote payload execution by upload

• Nginx without extra hardening • .htaccess won’t do much good

• In-DB PHP • PHP module

• Eval-uated code

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6.4 Forensics : outer droppings

• Filesystem : • <user>/www-data outside /sites

• www-data/www-data suspicious • « x » bit (0111) on files below docroot

• timestamps • ts(outside sites/*/files) = ts(install) • ts(exploits) > ts(install)

• meld with a fresh build from sources • Also check outside docroot / project root

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6.5 Forensics : Drupal modules

• Code signing/diffing : • Hacked! Limitations • D7 : md5check, file_integrity

• Finding DB PHP • OSInet QA (github)

• Misc • security_review

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6.6 Forensics : DB scans

• Quick wins : • users_field_data.email != users_field_data.init (users on D6/D7) • review roles, accounts with admin roles • On corporate sites, users_field_data.email domains • match users accounts with SSO data, directories

• Diff DB snapshot with live • D7: menu_router : file_put_contents, assert • D8: use vendor/bin/drupal debug:router instead of DB

• Altova DatabaseSpy content compare

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6.7 Forensics : session data

• Sessions should be in persistent storage • Remember when you pulled the plug • Were your sessions in Memcache ? in-memory Redis ?

• Quick checks: • sessions.timestamp vs users_field_data : created / changed / access / login • for intranets : sessions.hostname

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6.8 Forensics : logs• You use off-site logs, right ? • SaaS : Loggly, Logmatic,

Logsene, Logz.io, Papertrail, Scalyr…. • Homegrown remote ELK • GDPR • Data Processor constraints

(Rec. 81) • Record of processing

activities (Art. 30)

• Still on-site ? Read-write ? • dblog {watchdog} • syslog → redirects chain • mongodb_watchdog • redis_watchdog • GELF/Graylog, Logstash

• Application/WS logs

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6.9 Forensics : sleuth tools• Software • Guidance Software :

Encase • AccessData : Forensics

Toolkit (FTK) • Certified consultants • National cybercrime units

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7.1 Live again : restoring production

• On preprod, recheck notepad 1 findings vs new build • Usually, reset passwords. • On D8, use mass_pwreset • On D7/MySQL: • update users set pass = concat(‘ZZZ', sha(concat(pass, md5(rand()))));

• Prepare the GDPR Art. 34 exploit report • Prepare marketing/social copy • Prepare for the future

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7.2 L8R : future-readiness

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7.3 L8R: be prepared

• Developer education on security • Security Team mailing list • https://twitter.com/drupalsecurity • https://www.drupal.org/security/rss.xml • http://crackingdrupal.com/ ?

• National support • GDPR requires national authorities to

provide education (Art. 57, Rec. 122, 132) • Exists outside GDPR (FR: ANSSI MOOC)

https://secnumacademie.gouv.fr/

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https://twitter.com/drupalsecurity

https://www.drupal.org/security/rss.xml

http://crackingdrupal.com/

https://secnumacademie.gouv.fr/


7.4 L8R : disaster prevention

• Security process • Analyse sec. releases to

understand fixes • Look for similar flaw in

custom code • Take part in Drupal core /

contrib to acquire expertise

• Quality process • Systematic peer code reviews • Code-driver maintenance +

dev process • Automatic quality tools in CI • Contrib updates scheduling

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7.5 Continuous improvement

• « You can’t improve what you don’t measure » • Get time metrics from notepad 1 • Build contingency plan from notepad 2

• Plan for periodic intrusion simulations • GDPR Art. 32.1d: « …the controller and the processor shall

implement […] a process for regularly testing, assessing and evaluating the effectiveness of technical and organisational measures for ensuring the security of the processing »

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©2018 OSInet - Licensed under Creative Commons CC-BY-SA 4.0 42

Drupal, faster, safer http://www.osinet.fr/

@OSInethttps://www.linkedin.com/company/osinet/

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Documents

So you’ve been hacked… now what€¦ · • Anything you do leaves its own traces • Work on copies of the snapshots • You can restart from fresh copies anytime • There maybe