View source for Suji Yan Mask Network Founder Mobile Wallet Birthday Theft

{{Imported Case Study With About|source=https://www.quadrigainitiative.com/casestudy/sujiyanmasknetworkfoundermobilewalletbirthdaytheft.php}}
{{Unattributed Sources}}

[[File:Masknetworkyujisan.jpg|thumb|Mask Network Yuji San]]Suji Yan, founder and CEO of Mask Network, is a leading voice in the Web3 space. With a background in journalism and computer engineering, Suji has been a vocal advocate for privacy, digital sovereignty, and user empowerment. In 2022, he also launched Bonfire Union, a venture fund supporting overlooked founders in the decentralized tech ecosystem. On his 29th birthday, Suji reported a security breach where over $4 million in crypto assets were stolen from a wallet he managed via mobile phone. He suspects an offline attack may have occurred when his phone was briefly unattended during a private gathering. Despite immediate coordination with security experts and blockchain investigators, the funds—spread across multiple tokens like ETH, WETH, MASK, and USDT—have not been recovered.
<ref name="web3goinggreat-19385" /><ref name="web3isgreattweet-19386" /><ref name="yujisanhackannounce-19387" /><ref name="sujiyaninterview-19388" /><ref name="sujiyanplasmacon-19389" /><ref name="sujiyaniqwiki-19390" /><ref name="sujiyancrunchbase-19391" /><ref name="wublockchaintweet-19392" /><ref name="yujisanidm-19393" /><ref name="sujiyantweetdespite-19394" /><ref name="yujisanhackannouncecn-19395" /><ref name="yujisanontesting-19396" /><ref name="unknown-19397" /><ref name="sujiyantwitter-19398" /><ref name="cyversalertatweet-19399" /><ref name="thefireflyapptwitter-19400" /><ref name="sujiyantwitter-19401" /><ref name="sujiyantwitter-19402" /><ref name="sujiyantwitter-19403" /><ref name="sujiyantwitter-19404" /><ref name="sujiyantwitter-19405" /><ref name="sujiyantwitter-19406" /><ref name="etherscanethereum-19407" /><ref name="etherscanwrappedethereum-19408" />

== About Suji Yan ==
Suji Yan is a prominent entrepreneur and advocate for decentralized technologies and digital privacy. As the founder and CEO of Mask Network, he is best known for pioneering the integration of Web3 features into Web2 social platforms, allowing users to interact with decentralized applications, encrypt messages, and manage assets—all from within familiar interfaces like X (formerly Twitter) and Facebook.

Born in China, Suji Yan studied Computer Engineering at the University of Illinois Urbana-Champaign and briefly attended the University of Tokyo before dropping out to pursue entrepreneurship in 2017. Before founding his company, he worked as an independent journalist for outlets such as Caixin and Qdaily, where he developed a deep interest in AI, cryptocurrencies, and digital freedom.

Suji is a frequent speaker at blockchain and privacy-focused events, sharing his views on digital sovereignty, decentralized governance, and the importance of user-controlled systems. He envisions Mask as the "bridge" between the closed ecosystems of Web2 and the open potential of Web3, much like how DeFi disrupted traditional finance.

In 2022, Suji founded Bonfire Union, a venture capital initiative supporting underestimated founders in the Web3 space. He has also donated to institutions such as UIUC and RadicalxChange, supporting research and civic dialogue. Alongside his wife Katt Gu, Suji co-launched the anti-996 campaign, advocating for healthier work-life balance in tech.

Suji has received numerous accolades, including the JASSO Scholarship and awards from Hackathons hosted by Google and Intel. His early projects range from operating systems and weather apps to decentralized tech experiments. Notably, he has invested in or partnered with over a dozen Web3 ventures, including Soul Wallet, Transak, and 0xPPL.

Today, Suji leads Mask Network and serves as a board member at RSS3, continuing to expand the decentralized social internet. With a focus on user empowerment, privacy, and open-source collaboration, he remains a key figure in shaping the future of online interaction and digital identity.
== About Mask Network ==
Maintained by Dimension since 2019, Mask Network is a free, open-source project committed to building a secure and inclusive decentralized internet. The team invites developers and users alike to contribute and explore a new digital dimension together.

Launched in 2017, Mask Network received early funding from notable investors like Li Toyo. The platform has since grown into a robust suite of Web3 tools including encrypted posting, token swaps, decentralized identity, and NFT rendering—offering users a secure and user-friendly entry point into the decentralized web. Suji's work continues to challenge centralized social media by advocating for a layered approach to Web3 adoption rather than mass user migration.

Mask Network is a browser extension that bridges Web2 and Web3, allowing users to access encrypted messaging, decentralized profiles, and other Web3 services directly within social media platforms like X (formerly Twitter), Facebook, Instagram, Minds, and Mirror. It lets users enjoy traditional social media while seamlessly tapping into blockchain-based functionalities.

With Mask Network, users can experience features such as encrypted posts, NFT rendering, Snapshot voting, Gitcoin funding, Web3 file sharing, and scam warnings—directly in their social feeds. It transforms NFT links into interactive cards and supports tools like ENS search, token and NFT lookup, and integrated calendars.

Through the Next.ID protocol, Mask integrates decentralized identity verification, asset management, and wallet controls in a secure, cross-platform plugin. Its open-source, multi-chain wallet supports over 15 major EVM chains and offers asset tracking, token swaps, and dApp gateways—all in one interface.

Mask supports innovative Web3 apps like Lucky Drop (viral social giveaways), Smart Pay (Polygon-based contract wallet using Mask Token for gas), Web3 file storage (IPFS & Arweave), decentralized exchanges, ETH/stablecoin savings, wallet approval management, and fiat on-ramps for over 60 currencies.

Mask Network integrates with 30+ major Web3 projects and services including CoinGecko, ENS, Gitcoin, Snapshot, IPFS, OpenSea, Firefly, and Lens. It also supports leading wallets and chains, continually expanding its ecosystem.

== The Reality ==
Suji Yan was managing a large $4m+ wallet via his mobile phone.

== What Happened ==
Suji Yan, founder of the Mask Network, lost over $4 million in cryptocurrency due to a suspected wallet hack.
{| class="wikitable"
|+Key Event Timeline - Suji Yan Mask Network Founder Mobile Wallet Birthday Theft
!Date
!Event
!Description
|-
|February 26th, 2025 8:20:00 AM MST
|Yuji San ByBit Retweet
|Yuji San retweets information about the ByBit hack.
|-
|February 27th, 2025 2:49:59 AM MST
|Transfer Of Wrapped Ethereum
|923.817499554962882 wrapped ethereum are transfered from Suji Yan's wallet to the attacker.
|-
|February 27th, 2025 3:00:23 AM MST
|Transfer Of Ethereum
|113.063816357204803291 ethereum are transfered from Suji Yan's wallet to the attacker.
|-
|February 27th, 2025 5:31:00 AM MST
|Cyvers Alerts Tweet Posted
|Cyvers Alert posts that their AI-powered system has detected suspicious transactions involving Suji Yan, founder of @realMaskNetwork. Nearly $4 million in digital assets—including ETH, WETH, ezETH, weETH, pufET, MASK, USDT, and swETH—were sent to a suspicious address, then quickly swapped to ETH and distributed across six different wallets. Cyvers credits @zachxbt for swift and effective coordination in response to the incident.
|-
|February 27th, 2025 6:25:00 AM MST
|Yuji San Tweet Posted
|Yuji San posts that on his 29th birthday, a public wallet on his phone was hacked, resulting in the theft of over $4 million in assets across a series of manual transactions over 11 minutes. He suspects either a same-day key leak or a possible offline attack during a private gathering. Investigations are underway with the help of @SlowMist_Team, @zachxbt, and relevant authorities. Yuji urges transparency, stating that if this was an offline betrayal, the perpetrator should come forward—emphasizing that crypto should not remain a dark forest. The same post is made in Chinese several minutes later.
|-
|February 27th, 2025 6:51:00 AM MST
|Yuji San Getting Philosophical
|Yuji San expands on the Chinese translation of his post to add that he appreciates the public’s concern but urges everyone to remain rational and avoid speculation. While an offline attack is one possibility, he hopes it was not carried out by anyone he knows and has already brought in professionals to investigate. He clarifies that the stolen funds are his personal assets and have no connection to his company, its funds, or any affiliated projects—so there is no cause for concern on the business side. He ends with classical Chinese reflections on enduring hardship and personal growth in the face of adversity.
|-
|February 27th, 2025 11:18:00 AM MST
|Yuji San News Algorithm
|Suji Yan comments on how their story is appearing high in their news feed.
|-
|February 27th, 2025 12:54:00 PM MST
|Web3IsGoingGreat Post
|Web3IsGoingGreat posts about the incident: Suji Yan, founder of the Mask Network, lost over $4 million in cryptocurrency due to a suspected wallet hack. The theft occurred on his birthday while he was attending a private party, leading Yan to speculate that his private key may have been leaked or that the hack was executed through an offline attack during a brief moment when his phone was unattended.
|-
|February 28th, 2025 2:56:00 AM MST
|Suji Yan On FireFly
|Suji Yan posts an update related to the FireFly application, noting that the recent incident has driven the highest traffic the team has seen in the past year, with rapid growth. He clarifies that the stolen funds were his personal assets and not connected to company products, which remain secure. He encourages users to try out FireFly, emphasizes the platform’s strong security in the social space, and humbly acknowledges the need to improve his own security practices. He ends by calling for continued support for $MASK and @thefireflyapp.
|-
|February 28th, 2025 8:59:00 PM MST
|Untitled Event
|Suji Yan mentions the hack in a Tweet about meeting governor Terry Branstad.
|-
|February 28th, 2025 10:12:47 PM MST
|Yuji San Messages Hacker
|Yuji San sends a message to the hacker on the Ethereum blockchain warning that an international coalition involving the FBI, Hong Kong police, Interpol, and private security has identified and is actively pursuing them. The hacker is reportedly fully doxxed. The hacker is being provided a timeline of 72 hours to return the stolen funds and allowed a generous bounty. This is apparently the hacker’s only chance to walk away with anything—time is running out.
|-
|March 1st, 2025 4:21:00 PM MST
|Yuji San Message
|Wu Blockchain reports an on-chain message to the hacker "The FBI, Hong Kong police, Interpol, and private security personnel are working together and have identified and are pursuing you. Evidence of your actions has been obtained by us and our law enforcement partners. You have 72 hours to return the stolen funds before the situation escalates beyond control. Once the funds are returned, we will cease all tracking, destroy the collected data, and close the case. If you comply within this timeframe, we are willing to offer a generous bounty as a resolution reward."
|}

== Technical Details ==
Yuji San believes that there may have been an in-person attack on their mobile wallet, when they left their phone unattended during their birthday party.

== Total Amount Lost ==
Widely reported at $4m.

Assets reported by Cyvers:
"113 $ETH
923 $WETH
301 $ezETH
156 $weETH
90 $pufET
48.4K $MASK
50K $USDT
15 $swETH"


113 $ETH	113	2,237.91	252883.83
923 $WETH	923	2,237.91	2065590.93
301 $ezETH	301	2,237.91	673610.91
156 $weETH	156	2,237.91	349113.96
90 $pufETH	90	2,237.91	201411.9
48.4K $MASK	48400	2.2169	107297.96
50K $USDT	50000	1	50000
15 $swETH	15	2,237.91	33568.65
			3733478.14


The total amount lost has been estimated at $3,733,000 USD.

== Immediate Reactions ==
Yuji San posted a summary of the event on Twitter:

"I turned 29 yrs old today, 6 hours ago. Around 3 hours ago - one of my public wallet I carried on my phone was hacked and 4m$+ assets was stolen. All the stolen tx seems manual and span 11+ mins. 

So either the private key was leaked same day as my birthday and hacker manual tsf out or it might be an offline attack. I was in a private gathering with dozen friends and my phone was away for some minutes when I using the restroom etc. I trust my friends but this is a nightmare to anyone.

I’ve contacted @SlowMist_Team and @zachxbt to help the investigation and in cooperation with authorities and agencies. Before there are any outcome from these experts I will not say more. 

I hope if this is the offline case - you should confront me directly. Crypto is not a dark forest and I will not let it be."

== Ultimate Outcome ==
It does not appear that there is any update.

== Total Amount Recovered ==
It is believed that the funds were not recovered.

There do not appear to have been any funds recovered in this case.

== Ongoing Developments ==
What parts of this case are still remaining to be concluded?
== Individual Prevention Policies ==
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{{Prevention:Individuals:End}}

== Platform Prevention Policies ==
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{{Prevention:Platforms:End}}

== Regulatory Prevention Policies ==
{{Prevention:Regulators:Placeholder}}

{{Prevention:Regulators:End}}

== References ==
<references><ref name="web3goinggreat-19385">[https://www.web3isgoinggreat.com/?id=suji-yan-wallet-hack Founder of the Mask Network loses more than $4 million to a wallet hack - Web3IsGoingGreat] (Accessed Apr 25, 2025)</ref>

<ref name="web3isgreattweet-19386">[https://twitter.com/web3isgreat/status/1895200900253126786 Web3IsGoingGreat - "Founder of the Mask Wallet loses more than $4 million to a wallet hack" - Twitter/X] (Accessed Apr 25, 2025)</ref>

<ref name="yujisanhackannounce-19387">[https://twitter.com/suji_yan/status/1895103068808642811 Yuji San - "I turned 29 yrs old today, 6 hours ago. Around 3 hours ago - one of my public wallet I carried on my phone was hacked and 4m$+ assets was stolen. All the stolen tx seems manual and span 11+ mins." - Twitter/X] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyaninterview-19388">[https://www.youtube.com/watch?v=Y54odPSjNlA Bridging Web2 and Web3: Suji Yan on Mask Network's Vision - Defiant YouTube] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyanplasmacon-19389">[https://plasmacon.tech/sujiyan Suji Yan - Founder of Mask Network & Privacy Advocate - PlasmaCon] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyaniqwiki-19390">[https://iq.wiki/wiki/suji-yan Suji Yan - People in crypto - IQ.wiki] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyancrunchbase-19391">[https://www.crunchbase.com/person/suji-yan Suji Yan - Founder and CEO @ Mask Network - Crunchbase] (Accessed Apr 28, 2025)</ref>

<ref name="wublockchaintweet-19392">[https://twitter.com/wublockchain12/status/1895977649908171054 Wu Blockchain - "Wu said that according to the information on the chain, Mask Network founder Suji Yan sent a message to the hacker" - Twitter/X] (Accessed Apr 28, 2025)</ref>

<ref name="yujisanidm-19393">[https://etherscan.io/tx/0x3bb6f10ed3b22b1ef86e60869b969b4ecf7025f0c3aa9b29778e56c21bb6eb5f "There is an international effort between the FBI, Hong Kong police, Interpol, and private security operatives that has identified and is closing in on you, the perpetrator. You are fully doxxed and evidence of your actions is in our possession as well as our law enforcement partners." - EtherScan] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantweetdespite-19394">[https://twitter.com/suji_yan/status/1895685361205907545 Suji Yan - "Despite the recent personal hack, I’m glad to meet old friend governor Terry Branstad @TerryBranstad during eth Denver." - Twitter/X] (Accessed Apr 28, 2025)</ref>

<ref name="yujisanhackannouncecn-19395">[https://twitter.com/suji_yan/status/1895105333837648370 Yuji San Hack Announcement In Chinese - Twitter/X] (Accessed Apr 28, 2025)</ref>

<ref name="yujisanontesting-19396">[https://twitter.com/suji_yan/status/1895109489692680589 Yuji San - "When Heaven is about to confer a great responsibility on a man, it will first test his mind and will, exhaust his muscles and bones, starve his body, and deprive him of all poverty, and make his plans frustrated. This is to stimulate his heart and harden his nature, and increase his ability to do what he could not do before." - Twitter/X] (Accessed Apr 28, 2025)</ref>

<ref name="unknown-19397">[yujisan yujisan] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19398">[https://twitter.com/suji_yan/status/1895412816770929119 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="cyversalertatweet-19399">[https://twitter.com/CyversAlerts/status/1895089374582218823 Cyvers Alerts - "Our AI-powered system has detected suspicious transactions linked to @suji_yan, founder of @realMaskNetwork! A suspicious address received nearly $4M in digital assets" - Twitter/X] (Accessed Apr 28, 2025)</ref>

<ref name="thefireflyapptwitter-19400">[https://twitter.com/thefireflyapp/status/1895428452028973248 @thefireflyapp Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19401">[https://twitter.com/suji_yan/status/1895522341276512264 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19402">[https://twitter.com/suji_yan/status/1895548521933058244 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19403">[https://twitter.com/suji_yan/status/1895549224475115936 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19404">[https://twitter.com/suji_yan/status/1895555712836911371 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19405">[https://twitter.com/suji_yan/status/1895664195678683463 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="sujiyantwitter-19406">[https://twitter.com/suji_yan/status/1895665018076823614 @suji_yan Twitter] (Accessed Apr 28, 2025)</ref>

<ref name="etherscanethereum-19407">[https://etherscan.io/tx/0xeb1e43870d64e33395fdf4179cf2c7b5d29baea7a472e87f49327b62155b4e7b Transfer Of 113.063816357204803291 ETH - EtherScan] (Accessed Apr 28, 2025)</ref>

<ref name="etherscanwrappedethereum-19408">[https://etherscan.io/tx/0xee94f23a6a08c51cf2dd7092e83940d14d9d2e5e48a0a19e39c5a49a72359452 Transfer Of 923.817499554962882 WETH - EtherScan] (Accessed Apr 28, 2025)</ref></references>