Posts on Valtteri Lehtinen

After releasing the triangular arbitrage trading bot Harjus under MIT license and publishing a write-up on my journey last year, I took a brief stint of working on other stuff.

Note Read also the writeup on latest Harjus release.

Nmap has been my favorite hacking tool for years.

I don’t know what it tells about me, but I have a soft spot for prank calls.

DALL-E’s take on “A scary person holding rotten onion” In 2018, I read about the perfect crime of stealing the money of credit card fraudsters by making fake carding sites.

Remember UPnProxy?

While listening to Risky Business ep. 642, I learned about a botnet that has been abusing a vulnerability in TP-Link routers to provide SMS messaging as a service for years.

DNS Zone Transfer is a mechanism for administrators to replicate DNS datasets across DNS servers.

What kind of systems are there in the Finnish telephone network today?

I got interested in telephones and the Voice Over IP (VOIP) scene soon after reading Phil Lapsley’s Exploding the phone (2013).