Today, when you look for a well-known application on Google, you are more than likely to find dozens of download links from different websites. Even top-ranking links hide a lot of dangers. In this blog, you will see how a simple Chrome Extension for malware protection can safeguard you better than digital certificates or Google can.


The presence of a signing certificate is, in fact, not enough for trust and so is the source of the download. An increasing amount of malware and malware injected software, signed with legitimate digital certificates, are regularly distributed by highly ranked websites without being detected. A practice that exposes internet users to a lot of risks.


To confirm this thesis and quantify the level of risk that the average internet user is exposed to, I verified the integrity of popular applications by downloading them from the official websites and other highly ranked ones and comparing the hashes of the downloads.


Is my download bonafide and untampered software?


For my test, I used a very popular tool: PuTTY, the “as famous” open-source terminal emulator by Simon Tatham ( This tool counts millions of downloads and active users.


First, I installed CodeNotary Integrity Verification extension for Chrome by vChain. The extension protects internet users from installing malware, by automatically verifying the download unique hash to that of the official application, previously notarized with CodeNotary. If the hash does not correspond to the original, the user is altered so to avoid any dangerous installation. The extension is available here on the Chrome Web Store.


I, then, downloaded PuTTY from the official website. The extension confirmed that the software was original, obviously.


Putty integrity check CodeNotary

Testing the integrity of PuTTY Downloads


I then moved on with testing downloads of PuTTY for top-5 links. I have to say that Simon Tatham is doing a better job at SEO, with the link to the official download website landing first in google search. Nevertheless, amongst the top-5 links, I could find other suspicious download links.


We clicked on the first link that looked like it was from a respectable source:


Before doing that, we checked on McAfee Secure whether the website was a known malware publisher and the result was negative.


McAfee website verification

Also, in this case, vChain Chrome Extension immediately notified me that the file did not match to the version downloaded from official website resource.


In the case of PuTTY, McAfee WebAdvisor also alerted me that I was about to download a dangerous file and suggested me to interrupt the downloads. Ironically, that was the same Antivirus software which just a few seconds before gave me the green light on the website.


CodeNotary Integrity verification PuTTY

What are the main takeaways?


1. When downloading a software be aware of malicious copies. Some are benign replicas, but others include malware or undesired software.

2. You cannot rely on how well a website scores on SEO to trust software

3. Digital certificates do not protect you from malicious software


How CodeNotary Chrome extension protects you from malware?


As I said at the beginning of my post, up until today there was no easy way for internet users to verify if a download had been injected with malicious code. Even manual checks on website reliability and digital signatures verifiability proved to be insufficient for this task. In fact, today it’s quite common to find malware signed with official and legitimate digital certificates.


CodeNotary Download Integrity Verification extension for Chrome protects users from installing malware injected into any application, even famous ones, not that the level of notoriety matters. No manual verification, no searching the web, the extension automates everything for you.


If you are a software developer or a software publisher and you want to protect your customers from downloaded malware injected clones, start signing your code today with CodeNotary.  The solution is always free for Open Source and Non-commercial projects.


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Metrics and Logs

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Use Case - Tamper-resistant Clinical Trials


Blockchain PoCs were unsuccessful due to complexity and lack of developers.

Still the goal of data immutability as well as client verification is a crucial. Furthermore, the system needs to be easy to use and operate (allowing backup, maintenance windows aso.).


immudb is running in different datacenters across the globe. All clinical trial information is stored in immudb either as transactions or the pdf documents as a whole.

Having that single source of truth with versioned, timestamped, and cryptographically verifiable records, enables a whole new way of transparency and trust.

Use Case - Finance


Store the source data, the decision and the rule base for financial support from governments timestamped, verifiable.

A very important functionality is the ability to compare the historic decision (based on the past rulebase) with the rulebase at a different date. Fully cryptographic verifiable Time Travel queries are required to be able to achieve that comparison.


While the source data, rulebase and the documented decision are stored in verifiable Blobs in immudb, the transaction is stored using the relational layer of immudb.

That allows the use of immudb’s time travel capabilities to retrieve verified historic data and recalculate with the most recent rulebase.

Use Case - eCommerce and NFT marketplace


No matter if it’s an eCommerce platform or NFT marketplace, the goals are similar:

  • High amount of transactions (potentially millions a second)
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  • prevent overwrite or updates on transactions
  • comply with regulations (PCI, GDPR, …)


immudb is typically scaled out using Hyperscaler (i. e. AWS, Google Cloud, Microsoft Azure) distributed across the Globe. Auditors are also distributed to track the verification proof over time. Additionally, the shop or marketplace applications store immudb cryptographic state information. That high level of integrity and tamper-evidence while maintaining a very high transaction speed is key for companies to chose immudb.

Use Case - IoT Sensor Data


IoT sensor data received by devices collecting environment data needs to be stored locally in a cryptographically verifiable manner until the data is transferred to a central datacenter. The data integrity needs to be verifiable at any given point in time and while in transit.


immudb runs embedded on the IoT device itself and is consistently audited by external probes. The data transfer to audit is minimal and works even with minimum bandwidth and unreliable connections.

Whenever the IoT devices are connected to a high bandwidth, the data transfer happens to a data center (large immudb deployment) and the source and destination date integrity is fully verified.

Use Case - DevOps Evidence


CI/CD and application build logs need to be stored auditable and tamper-evident.
A very high Performance is required as the system should not slow down any build process.
Scalability is key as billions of artifacts are expected within the next years.
Next to a possibility of integrity validation, data needs to be retrievable by pipeline job id or digital asset checksum.


As part of the CI/CD audit functionality, data is stored within immudb using the Key/Value functionality. Key is either the CI/CD job id (i. e. Jenkins or GitLab) or the checksum of the resulting build or container image.

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