
11 Oct 2016
How to Prevent DDoS Attacks on a Cloud Server Using Open Source Software
A Distributed Denial of Service Attack (DDoS) is, unfortunately, an increasingly common form of premeditated attack against an organization’s web infrastructure.
Typically, it involves using multiple external systems to flood the target system with requests with the intention of overwhelming the system with network traffic. These attacks work because an unprotected system may find it difficult to differentiate between genuine traffic and DDoS traffic.
If you are using a Virtual Private Server (VPS) or Cloud Server, then this article will help you understand which open source software you can use to prevent DDoS attacks.
DDoS Deflate
DDos Deflate is a lightweight open source shell script that you can easily implement on your server and configure to mitigate most DDoS attacks.
Here are some of the features of DDoS Deflate:
- It can automatically detect rules within iptables or an Advanced Policy Firewall (APF).
- Ability to block IP addresses temporarily (the default setting is 30 mins).
- Whitelist and blacklist features for blocking or allowing connections to the server.
- Management features to notify administrator of actions taken.
Fail2Ban
Fail2ban works in a similar way to DDoS Deflate, as it also bans traffic based on malicious IP address profiling.
It’s a good performer and some of the main features are as follows:
- Easy to configure with some automation features included.
- Compatible with existing firewalls, e.g. iptables.
- Customizable blacklisting and whitelisting features.
- Ability to block automated brute force attacks.
- Time-based IP blocking.
Fail2Ban is good option for any web server that has SSH and few other services.
Apache mod_evasive module
The mod_evasive module is suited to protecting Apache web servers against DDoS attacks. It also includes notification features via email and SYSLOG.
This module is a strong performer, which has the added benefit of adapting to real time situations by creating rules on the fly based on the following patterns being detected:
- Requesting access to the same page too many times per second.
- Making 50 concurrent connections to the same child process per second.
- Making other requests from blacklisted IP addresses.
Some of the features which are available to prevent DDoS attacks are as follows:
- The server administrator can limit access to certain pages based on the number of requests one particular IP can make (DOSPageCount option).
- Access to an entire website can be limited based on how many connections one particular IP makes using the DOSSiteCount option.
- The DOSHashTable feature can monitor who is accessing what in the web server based on their previous visits and can make a decision whether to allow or block the connection.
The administrator can be notified via email of what action Apache mod_evasive is taking.
Mod_evasive is relatively easy to use and because the open source modules are built into Apache, it’s free to use.
FastNetMon
FastNetMon is another high performance DDoS mitigation tool which was based on a packet analyzer engine (PF_RING, sFLOW, Netflow, PCAP).
Below are some of the main features of FastNetMon:
Features:
- Handles both incoming and outgoing traffic.
- Support of trigger block script if IP load network threshold of packets per second or bytes per second exceeded.
- It can untag VLANs so it can separate different networks.
- Capable of deciphering networks used in high performance telecommunication.
- It can decrypt encrypted protocols to investigate malicious packets.
- It can reroute DDoS traffic to ‘black hole’.
- Works well in mirrored networks.
- Can work on server/soft (virtual) router.
- High performance - can detect DoS/DDoS in 1-2 seconds.
- High compatibility - works with Ubuntu, Free BSD, Mac OS and has been Tested up to 10GE with 5-6 Mpps on Intel i7 2600 with Intel Nic 82599.
HAPROXY
HaProxy is an excellent open source load balancing tool that is also effective against DDoS attacks against a cloud server.
It has the following features:
- It can block traffic based on the bandwidth.
- Contains blacklist and whitelist tables of IPs which it builds into its configuration based on the rule set.
- Ability to block IPs which might be performing DDoS attacks.
- HaProxy can identify bots, which is why it’s effective against DDoS attacks.
- Can prevent Syn Flood type attacks as well as capabilities like connection limitations etc.
DDOSMON
Another low level DDoS monitoring and mitigation tool is DDOSMON. It can monitor traffic with possible attacks and it reacts by alerting and triggering user defined actions based on the type of attack.
It is capable of detecting the following attacks successfully:
It detects the attack, sends an email notification to the administrator and takes corrective actions.
NGINX
As well as being a popular load balancing tool which sits on top of Apache, NGINX also has powerful built in DDoS attack mitigation capabilities.
Some of the DDoS features of NGINX are:
- Rate limits, identification of concurrent IPs to limit access based on the client IP addresses.
- Ability to block clients based on their geo-location using the ngx_http_geo_module. Using this feature, whole countries can be blocked if required.
- It can identify agents by checking their flash and JavaScript capabilities.
- Can be combined with HaProxy for additional protection against DDoS.
Summary
These are some of the most popular, easy to use, but also very effective DDoS protection tools for safeguarding your cloud server. Between them, they should offer most server administrators the ability to protect their server against the risk of DDoS attacks.
Tony is passionate about helping his clients get the most out of their online presence. He is the co-founder of Pickaweb and Author of the 5 Star Amazon rated book ‘The Lazy Website Syndrome’, which gives the reader a simple 3 step approach to grow their business using online marketing. Tony currently resides in the South of Spain.
Pickaweb offers a full range of services for SME’s including Domain Names, Web Hosting, Reseller Hosting, Virtual Private Servers, Cloud Servers, Dedicated Servers, SSL Certificates and an easy to use Website Builder.
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GlobalSign Privacy Policy Version 3.0
Updated April 1, 2018
GlobalSign respects your right to privacy.This privacy policy has been developed to inform you about the privacy practices followed by GlobalSign in connection with its websites, products and services. This privacy policy does not apply to GlobalSign services offered by or through our partners, resellers or other third parties, or other third party services or websites, and we encourage you to read the privacy policies of those parties.
This privacy policy will inform you about what data is collected, how we use such data, where data is processed, how you may opt out of your data being used, the security provisions around storing your data and how to correct or update your data.
1. Data Controller
In order to communicate with you and to provide our products and services and related support, it is necessary for GlobalSign to transfer your personal data outside of the European Union. In such case, the data controller for this data for EU residents is GMO GlobalSign, Ltd., having its registered offices at Springfield House, Sandling Road, Maidstone, Kent, ME14 2LP, United Kingdom. All questions or requests regarding the processing of data may be addressed to: dpo@globalsign.com.
2. Collection of Personal Information
We collect information from you when you (i) place an order for a GlobalSign digital certificate product or other product or service, (ii) scan your servers for digital certificates using our Certificate Inventory Tool (CIT), (iii) apply for access to our managed service platforms, (iv) subscribe to our newsletter, (v) use our online chat service, (vi) download a white paper, (vii) register for a webinar, (viii) respond to a survey, (ix) fill out a form for pre/post sales assistance, (x) open a support ticket, or (xi) your use of social media.
GlobalSign is a Certification Authority and trusted third party. To fulfill requests for digital certificates or other products or services, you may be asked to enter your name, email address, physical address, phone number, credit card information and/or organizational details or other personal information.
We may develop and acquire additional information about you using third-party sources, browsing, and purchasing history, and so on in order to process certificate requests and to improve our services.
GlobalSign treats personal information as confidential, except for the information included in an issued digital certificate. Such information may be verified using third party commercial and government resources, and as such, is deemed to be public information.
3. Use of Personal Information
Your information, whether public or private, will not be sold, exchanged, transferred outside of our group company, or given to any other company for any reason without your consent, other than for the purposes specified in below:
3.1 To process applications for GlobalSign products and services
Your information is used to provide our products and services and order processing as well as to conduct business transactions such as billing.
3.2 To improve customer service
Your information helps us to more effectively respond to your pre/post sales requests and provide technical support.
3.3 To send renewal notices
The email address you provide for order processing may be used to send you renewal notices for your expiring digital certificate.
3.4 To send periodic emails
In addition, we may send you periodic company newsletters, new service updates, security updates, related product or service information, and status updates on maintenance windows or service availability.
3.5 To tell you about our products and services
We may send you information about our products and services that may be of interest to you based on your use of other GlobalSign products and services, your attendance at GlobalSign sponsored marketing events such as webinars, your requests for information about similar products and services, or your sharing of data with social media sites such as LinkedIn or Facebook.
4. Processing of Data and Consent
We will process your data for the purpose of performance of our contract with you or the legitimate interest of our business. In other cases, we will request your consent for the processing of the personal data you may submit.
Your refusal to provide personal data to us for certain products and services may hinder us from fulfilling your order for those products or services. Also, if you deny or withdraw your consent to use personal data or opt out of receiving information about GlobalSign products and services this may result in you not being made aware of sales promotions, renewal notices, periodic company newsletters, new service updates, security updates, related product or service information, and status updates on maintenance windows or service availability.
5. Use of Cookies and web beacons
The GlobalSign Certificate Center (GCC) uses cookies to enable the fulfillment of services. Cookies may be used when you log into the GCC, purchase products or use certain GCC functions.
In addition, like most online businesses, GlobalSign uses cookies and web beacons on our websites and through marketing related emails to gather and analyze some personal data such as the visitor’s IP address, browser type, ISP, referring page, operating system, date/time and basic geographical information.
We use cookies and web beacons to compile aggregate data about site traffic and site interaction so that we can gauge the effectiveness of our communications and offer better site experiences and tools in the future. We may contract with third-party service providers to assist us in better understanding our site visitors. These service providers are not permitted to use the information collected on our behalf except to help us conduct and improve our business.
First time visitors may choose to not have any activity monitoring cookies set in their browser. We use an opt-out identification cookie to tag these users as having made this decision. Those cookies that pertain to site performance, experience improvement and marketing are programmed not to execute when an opt-out cookie is present in a visitor’s browser. Opt-out cookies persist until a visitor clears their browser cookies, or until their expiration one year after the set date. A visitor is required to opt out again after one year in order to disable any activity monitoring cookies.
More details of GlobalSign’s use of cookies can be found on our website at https://www.globalsign.com/en/repository/cookie-policy/
6. Use of application logs for diagnostics or to gather statistical information
Our servers automatically record information ("Application Log Data") created by your use of our services. Application Log Data may include information such as your IP address, browser type, operating system, the referring web page, pages visited, location, your mobile carrier, device and application IDs, search terms, and cookie information. We use this information to diagnose and improve our services. Except as stated in section 8 (Data Retention), we will either delete the Application Log Data or remove any account identifiers, such as your username, full IP address, or email address, after 12 months.
7. Sharing of Information and Transfers of Data
We do not sell or trade your personal information to outside parties.
GlobalSign is a global organization with business processes and technical systems in various countries. As such, we may share information about you within our group company and transfer it to countries in the world where we do business in connection with the uses identified in section 3 above and in accordance with this Privacy Policy. In these cases, personal data will be transferred to countries that do not provide an adequate level of protection under European law so we ensure your data is protected by entering into agreements containing standard contract clauses with each of our group companies a copy of which may be obtained by contacting us as outlined in section 15 below.
We may also transfer your personal data to trusted third parties in order to serve purposes that are specified in section 3 above. In circumstances where data is shared with such third parties, they are required to agree to confidentiality terms. This prohibits such third parties from selling, trading, using, marketing or otherwise distributing GlobalSign customer data.
We may also release your information when we believe release is appropriate to comply with the law or protect our rights, property, or safety.
It is our policy to notify customers of requests for their data from law enforcement unless we are prohibited from doing so by statute or court order. Law enforcement officials who believe that notification would jeopardize an investigation should obtain an appropriate court order or other process that specifically precludes member notification, such as an order issued pursuant to 18 U.S.C. §2705(b).
We may also disclose your personal information to third parties who may take over the operation of our site or who may purchase any or all of our assets, including your personal information. We will contact you using the details you provide if there is any change in the person controlling your information.
8. Data retention
The personal information we collect is retained for no longer than necessary to fulfil the stated purposes in section 2 above or for a period specifically required by law or regulation that GlobalSign is obligated to follow.
To meet public CA audit requirements as detailed in the GlobalSign Certification Practice Statement, personal data used to fulfill verification of certain types of digital certificate applications will be retained for a minimum of 10 years depending on the class of product or service and may be retained in either a physical or electronic format. Please refer to the GlobalSign Certification Practice Statement for full details.
Even if you request deletion or erasure of your data, we may retain your personal data to the extent necessary and for so long as necessary for our legitimate business interests or performance of contractual obligations.
After the retention period is over, GlobalSign securely disposes or anonymizes your personal information in order to prevent loss, theft, misuse, or unauthorized access.
9. Opting out; withdrawing consent
If at any time you would like to unsubscribe from receiving future emails, we include unsubscribe instructions at the bottom of each email.
Renewal notices may be cancelled on a per digital certificate basis by logging into your GlobalSign Certificate Center (GCC) account and disabling renewal notices.
Email preferences for CIT related/collected information can be updated and changed within CIT.
If GlobalSign is processing your personal data based on your consent, you may withdraw your consent at any time by contacting us at one of the addresses shown in section 15 below.
10. Acess to your personal data
You are responsible for providing Globalsign with true, accurate, current and complete personal information. Also you are responsible to maintain and promptly update the information to keep it true, accurate, current and complete.
You have the right to access and modify your personal data stored on GlobalSign systems.
You can request to access or modify your personal information by contacting us in writing. We will require you to provide identification in order to verify the authenticity as the data subject. We will make reasonable effort to respond to and process your request in a timely manner.
If you provide any information that is untrue, inaccurate, not current or incomplete, or if we have reasonable grounds to suspect that such information is untrue, inaccurate, not current or incomplete, we have the right to suspend or terminate your account and refuse any and all current or future services.
11. How we protect your information
We implement a variety of security measures to maintain the safety of your personal information when you place an order or enter, submit, or access your personal information. All supplied sensitive/credit information is transmitted via Secure Socket Layer (SSL).
After a transaction, your transaction-related information will be kept on file to meet audit requirements and facilitate renewals. We do not retain any credit card details.
GlobalSign uses a reputable third party to process credit card payments and needs to provide credit card numbers and identifying financial data directly to the third party credit card processor. Such information is shared securely.
12. Follow relevant laws
GlobalSign commits itself to protect the personal information submitted by applicants and subscribers for its public certification services. GlobalSign declares to fully respect all rights established and laid out in European laws and operates within the limits of the:
- European Directive 95/46 on the protection of individuals with regard to the processing of personal data and on the free movement of such data; and
- Provisions of the GlobalSign CPS.
13. Your rights
In compliance with the European Union rules on privacy, you have the following rights established by law:
- We use the data you submit only for purposes identified in section 3 of this privacy policy.
- You have the right to review your personal data that GlobalSign holds and check it for accuracy.
- You have the right to correct data in the case that errors may be found in our records.
- You have the right to request that any of your personal data be erased. i.e. right to be forgotten.
- You have the right to obtain and reuse use your personal data for your own purposes
- You have the right to request that GlobalSign restrict the processing of your personal data under certain circumstances.
- You have the right to object to our processing of your personal data.
14. Changes to our Privacy Policy
If we make material changes to our privacy policy, we will inform customers by emailing a notice of the availability of a new version with a link to the new version.
15. Contact Us
If you have any inquires, or questions regarding our privacy policy, please contact us at:
https://support.globalsign.com/
https://www.globalsign.com/en/company/contact/support/
https://jp.globalsign.com/support/
or
Deputy Data Protection Officer
GMO GlobalSign, Ltd.
Springfield House Sandling Road
Maidstone, Kent ME 14 2LP
United Kingdom
dpo@globalsign.com
16. Our Office Locations
GMO GlobalSign K.K., Tokyo, Japan
GMO GlobalSign Ltd., Maidstone, Kent, UK
GMO GlobalSign N/V, Leuven, Belgium
GMO GlobalSign, Inc., Portsmouth, NH, USA
GMO GlobalSign Russia LLC , Moskva, Russia
GMO GlobalSign Pte. Ltd, Anson, Singapore
GMO GlobalSign Certificate Services Pvt. Ltd., Delhi, India
GlobalSign China Co., Ltd., Shanghai, China
GMO GlobalSign Inc., Manila, Philippines
GMO GlobalSign FZ-LLC, Dubai, UAE