Computer Security Introduction

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Kicksecure comes with many security featuresarchive.org. Kicksecure is Security Hardened by default and also provides extensive Documentation including a System Hardening Checklist. The more you know, the safer you can be.

This page is an introduction to computer security.

Introduction[edit]

Kicksecure first time users warning Before reviewing chapters in the Computer Security section, be sure to also read the Warning page.

Info Wiki entries in this section purposefully focus on:

  • General computing security information.
  • Host operating system security advice.
  • Preparatory steps before installing Kicksecure using a Type I hypervisor (Kicksecure for Qubes) or a Type II hypervisor like VirtualBox or KVM.

Essentials[edit]

Info "Security is a process, not a product." -- Bruce Schneier, encryption and security expert. [1] [2]

It is important to understand that Kicksecure and all general software cannot guarantee absolute anonymity or security; 'perfect security' is a mirage. The reason is flaws in hardware and software are ever-present, as continual upgrades and patches inevitably introduce further coding [3] or design errors which attackers of varying skill can profit from. As a consequence, the best approach is to try and mitigate risk exposure and provide defense in depth. [1] [4]

With this understanding, a material improvement in security and anonymity requires 'raising the bar' against potential attackers and eavesdroppers: [5]

Security is a process, not a product. It is also about economics. Briefly explained, each attacker has a set of capabilities, privileges, and a certain amount of budget, time and motivation. Given enough of these resources, security of any process will fail; the goal when securing a system is to add layers of security that make attacks too expensive. Nation-state actors have massive budgets, and no single system can be made secure enough against targeted attacks. However, if widely deployed, systems that cannot be compromised with automated attacks, increase the attacker's cost linearly and thus force the attacker to pick targets. Such systems are the only way to make mass surveillance infeasibly expensive.

If you have more time available, then it is recommended to read the Documentation widely.

Motivation[edit]

If motivation is needed to secure your computer, refer to these articles:

If the reader is time-poor, then just review the Hacked PCarchive.org or Hacked Emailarchive.org figures, or briefly scan the summary tables below.

Hacked PC[edit]

US journalist and investigative reporter Brian Krebs notes there are a large number of malicious uses for hacked PCs, including ransomware, bot activity, stolen account credentials, webmail spam and much more.

Table: Value of a Hacked PC [6]

Category Attacker Activity
Account Credentials eBay/Paypal fake auctions

Online gaming, website FTP, Skype/VoIP credentials
Client-side encryption certificates

Bot Activity Zombies: spam, DDoS extortion, click fraud and CAPTCHA-solving

Anonymization proxy

Email Attacks Webmail spam

Stranded abroad advance scams
Harvesting email contacts and associated accounts
Access to corporate email

Financial Credentials Bank account and credit card data

Stock trading account
Mutual fund / 401k account

Hostage Attacks Fake anti-virus

Ransomware and email account ransom
Webcam image extortion

Reputation Hijacking Facebook, Twitter, LinkedIn, Google
Virtual Goods Online gaming characters, goods/currency

OS and PC game license keys

Web Server Phishing, malware download site

Warez/privacy, child pornography server
Spam site

Hacked Email Account[edit]

Krebs also notes the significant value of a hacked email account. Just one breach of an online email service permits the theft of valuable personal data, account/contact harvesting, re-sale of retail accounts, spam and much more. An email account is a particularly weak link, since once under the attacker's control they can reset the password, along with the passwords of many linked services and accounts.

Table: Value of a Hacked Email Account [7]

Category Attacker Activity
Employment Forwarded work documents and work email

Fedex, UPS, Pitney Bowes account
Salesforce, ADP accounts

Financial Bank accounts

Email account ransom
Change of billing
Cyberheist lure

Harvesting Email, chat contacts

File hosting accounts
Google Docs, MS Drive, Dropbox, Box.com
Software license keys

Privacy Your messages, calendar, photos, Google/Skype chats

Call records (+ mobile account)
Your location (+ mobile/itunes)

Retail Resale Facebook, Twitter, Tumbler, Macys, Amazon, Walmart

i-Tunes, Skype, Bestbuy, Spotify, Hulu+, Netflix
Origin, Steam, Crossfire

Spam Commercial email

Phishing, malware
Stranded abroad, email signature and Facebook/Twitter scams

General Advice[edit]

Achieving greater security depends on how much time the user is willing to invest in Kicksecure configuration. Security also rests upon the daily practices and procedures that have been adopted by the user, see Documentation.

Backups[edit]

Info It is important to store multiple, encrypted backups of sensitive data.

If the user does not possess at least two copies of the original data, then it should be considered lost. The reason is data on one medium might become inaccessible and beyond repair at any minute. In this case, the computer would not even detect the risk, so data recovery tools would not be of help either. [8]

Best practice recommendations:

  • Store the original, encrypted file on a medium like the internal hard drive.
  • Create a first encrypted backup: for example, on an external hard drive from manufacturer A.
  • Create a second encrypted backup: for example, on an external hard drive from manufacturer B.

For greater security and to protect from incidents like fire or theft, backups in separate physical locations are recommended. Additionally, backups can be stored on remote servers, but the user must be sure it is encrypted properly. [9]

Safer Upgrades[edit]

  • Kicksecure: If running VM instances are not shutdown, there is a cross-contamination risk for new machines being imported into the virtualizer. For example, this is possible if a powerful adversary has taken control over those VMs currently in use. This action is not required if the user intends to create a new virtual network for the machines being imported.
  • Kicksecure-Qubes: Before upgrading Kicksecure Templates, close as many open VMs as possible. Do not run VMs from different domains at the same time as upgrading.

File Storage Location[edit]

It is unsafe to store files directly in the root section of the home folder (like /home/user). [10] It is far better to use a sub-folder and store the file there, for example:

  • Non-ideal storage location: /home/user/some-document
  • Safer storage location: /home/user/my-documents/some-document

The following sub-folders in the home directory should also be avoided: [11]

  • ~/tmp
  • ~/Download
  • ~/Downloads
  • ~/download
  • ~/downloads
  • ~/Desktop

If files are downloaded to the ~/Downloads folder -- the only folder available if the Tor Browser AppArmor profile is enforced -- then move them elsewhere. A folder of your own choosing will keep its contents private from any confined application that is later (hypothetically) compromised.

Other folders that should also be avoided include: [12]

  • /media
  • /srv
  • /net

It is easy to choose folder names which are better than the default naming convention. As soon as a user prepends or appends a random number or string to a folder (such as my-), this makes it unlikely that AppArmor profiles or possibly other mandatory access control frameworks will allow access to these folders by default.

Another reason is that some commands such as sudo rm -rf /var/lib/apt/lists/* (sometimes useful in case of APT issues) are unsafe if a typo is made. If a space is added before the asterisk symbol ("*") by mistake then this would by default delete all files (except hidden files) in the user's current folder (often the home folder). (But not folders in that folder). [13]

Known Bugs[edit]

To learn about known bugs affecting all platforms, see here. Refer to the issue tracker for a list of all all open issues affecting Kicksecure.

Greater Security and Next Steps[edit]

After reading and applying relevant steps outlined in this section:

In all cases, users should follow the Post-installation Security Advice.

For greater security pre- and post-Kicksecure installation, users should read the Documentation pages widely to learn more about potential threats and mitigations. For instance, users might like to consult the Design pages, and consider the recommendations outlined in the Basic Security Guide and Advanced Security Guide sections. Users with limited time can refer to the System Hardening Checklist.

Stay Tuned[edit]

It is recommended to read the latest Kicksecure news to stay in touch with ongoing developments, such as notifications about important security vulnerabilities, improved Kicksecure releases, other software updates and additional advice.

Advanced Security Guide[edit]

After reading this chapter, it is recommended to refer to the [Advanced_Security_Guide_Introduction Advanced Security Guide Introduction] section for even more security advice.

Footnotes[edit]

  1. 1.0 1.1 https://www.schneier.com/essays/archives/2000/04/the_process_of_secur.htmlarchive.org
  2. In other words, security is a continual process -- not an end destination -- that is informed by new knowledge that is constantly gathered.
  3. Security bugs generally fall into two categories: those which pose a passive threat due to eventual erroneous behavior, and the introduction of accidental vulnerabilities that are exploitable with malicious inputs.
  4. Schneier also notes several other security principles: limit privilege, secure the weakest link, use choke points, fail securely, leverage unpredictability, enlist the users, embrace simplicity, detect attackers, respond to attackers, be vigilant, and watch the watchers.
  5. https://github.com/maqp/tfc/wiki/Threat-modelarchive.org
  6. https://krebsonsecurity.com/2012/10/the-scrap-value-of-a-hacked-pc-revisited/archive.org Figure 1.
  7. https://krebsonsecurity.com/2013/06/the-value-of-a-hacked-email-account/archive.org Figure 1.
  8. In such cases the user might get lucky with professional data recovery companies, but the usual cost is a few thousand dollars.
  9. That is, with a recommended encryption method and a suitably long passphrase.
  10. This is because AppArmor profiles (and possibly other mandatory access control frameworks) are often required to grant read access to the root home folder due to technical limitations.
  11. /etc/apparmor.d/abstractions/user-download
  12. /etc/apparmor.d/abstractions/ubuntu-browsers.d/user-files
  13. Because deleting folders requires rm -r.

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