On a recent Thursday, the hackers’ targets appeared to be a Silicon Valley food delivery start-up, a major Manhattan law firm, one of the world’s biggest airlines, a prominent Southern university and a smattering of targets across Thailand and Malaysia.

The activity had the hallmarks of Chinese hackers known as the Codoso group, a collection of hackers for hire that the security industry has been tracking for years. Over the years, the group has breached banks, law firms and tech companies, and once hijacked the Forbes website to try to infect visitors’ computers with malware.

Remarkably, many attacks rely on a tangled maze of compromised computers including those mom-and-pop shops like Cate Machine & Welding. The hackers aren’t after the Cates’ data. Rather, they have converted their server, and others like it, into launchpads for their attacks.

These servers offer the perfect cover. They aren’t terribly well protected, and rarely, if ever, do the owners discover that their computers have become conduits for spies and digital thieves. And who would suspect the Cate family?

These are not random attacks. They're practicing. 

Mr. Darché wanted to add the Cates’ server to Area 1’s network of 50 others that had been co-opted by hackers. Area 1 monitors the activity flowing into and out of these computers to glean insights into attackers’ methods, tools and websites so that it can block them from hitting its clients’ networks, or give them a heads-up days, weeks or even months before they hit.

.Hackers don’t just press a big red “attack” button one day. They do reconnaissance, scout out employees on LinkedIn, draft carefully worded emails to trick unsuspecting employees to open them and click on links or email attachments that will try to launch malicious attacks.

Once they persuade a target to click — and 91 percent of attacks start this way, according to Trend Micro, the security firm — it takes time to crawl through a victim’s network to find something worth taking. Then they have to pull that data off the network. The process can take weeks, months, even years and leaves a digital trail.

Area 1 watches for this kind of activity and then teams up with firms like Blue Coat, a web security company, to build what it has learned into security software that can try to block attacks when they come.

It starts with social engineering.