# Marcin Kleczynski, CEO at Malwarebytes

> Marcin Kleczynski, CEO at Malwarebytes. 2 investments on record. The rounds they were named in and the filings that name them, each with its source.

Source: https://millionrounds.com/person/marcin-kleczynski (Millionrounds; every figure on the page links to its filing or article)

Los Altos, US · Angel

# Marcin Kleczynski

CEO at Malwarebytes

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Latest rounds

- **Rithmio** Seed · $3M Jun 2015
- **Rithmio** Seed · $650k Sept 2014

Backs *IT Services*

Profile summary

- **Rounds named:** 2 last Jun 2015
- **Filings:** - with regulators
- **Podcasts:** 1 episodes

What this record rests on

- ✓ **Named in rounds** 2 rounds name them
- **On filings** No filing names them
- **Linked to a firm** No firm on record
- **Claimed** Not claimed yet

Titles come from the investor lists this database was built from, so read them as of their date.

[Correct or remove](https://millionrounds.com/corrections?person=marcin-kleczynski)[Is this you? Claim it](https://millionrounds.com/claim?person=marcin-kleczynski)

## Rounds they were named in

- **Rounds:** 2
- **Led:** 0
- **Disclosed:** $3.6M
- **Active:** 2014–15

2015

- [Rithmio](https://millionrounds.com/company/rithmio) *Seed* **$3M** *US* Jun 2015 Joined · +9 investors · historical

2014

- [Rithmio](https://millionrounds.com/company/rithmio) *Seed* **$650k** *US* Sept 2014 Joined · +5 investors · historical

By stage

- Seed **2**

What they backed

IT Services **2**

Alongside

- [Hyde Park Venture Partners *2*](https://millionrounds.com/fund/hyde-park-venture-partners)
- [Serra Ventures *2*](https://millionrounds.com/fund/serra-ventures)
- [Foley Ventures *1*](https://millionrounds.com/fund/foley-ventures)
- [Fox Ventures *1*](https://millionrounds.com/fund/fox-ventures)
- [Hyde Park Angels *1*](https://millionrounds.com/fund/hyde-park-angels)
- [Illinois Ventures *1*](https://millionrounds.com/fund/illinois-ventures)
- [Intel Capital *1*](https://millionrounds.com/fund/intel-capital)
- [KGC Capital *1*](https://millionrounds.com/fund/kgc-capital)

Rounds where a report named this person rather than a firm, matched on name: read it as a strong hint, not proof, since people share names.

## Companies they are listed as backing

Portfolio

- [Netacea](https://millionrounds.com/startup/netacea)
- [Occasion](https://millionrounds.com/startup/occasion)
- [Rithmio](https://millionrounds.com/startup/rithmio)

## Hear them before you pitch them

- [Grit](https://millionrounds.com/podcasts/grit) · 23 Feb 2026 · 1h 3m The AI Era of Cybercrime: How Malwarebytes Is Evolving Its Security Stack | Marcin Kleczynski With [Marcin Kleczynski](https://millionrounds.com/person/marcin-kleczynski) About this episode What began as a 14 year old fixing infected computers became Malwarebytes, an 800 person cybersecurity company trusted by millions of customers. On Grit, Marcin Kleczynski joins Joubin Mirzadegan to explore AI driven cyber threats, strategic reinvention, and the discipline of evolving before the… More on the show's page Listen on Apple PodcastsThe show's page

Episodes of [the shows we follow](https://millionrounds.com/podcasts), matched by name. Not them? [Tell us](https://millionrounds.com/corrections?person=marcin-kleczynski).

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