Phone farms

A phone farm (also called a device farm) is a setup of hundreds to thousands of real phones kept in one place and controlled centrally by software, used to generate app installs, views, engagement or accounts that look like they come from many different people. In app advertising, phone farms are a major source of fake installs.

What is a phone farm?

Unlike bots running on emulators, phone farms use real hardware, often old phones lined up in racks. Because the devices are real, installs from a phone farm pass many basic device checks that an emulator would fail.

The Media Rating Council classifies automated activity from specialized devices, including emulators and automation software, as sophisticated invalid traffic (SIVT): the kind that can only be detected by analyzing many signals together (MRC, IVT Standards Addendum, June 2020).

Phone farms and click farms often get mixed up. The term click farm puts the emphasis on people hired to click, watch and leave reviews. Phone farm puts it on the device racks and automated scripts, where one person can run a thousand phones.

A case in Vietnam reported by VTV (September 2026)

The Cybersecurity and High-Tech Crime Prevention Division of the Da Nang City Police found a system of more than 2,000 phones and more than 100 CPUs inside an apartment, connected via USB, LAN or dedicated boxes and controlled by a single server. Custom-written software let one server run thousands of fake accounts at the same time to engage with content and push scam links (Thị trường Tài chính Tiền tệ magazine, September 2026). This operation served scams, but the same infrastructure only needs a different script to start farming app installs.

How do phone farms fake installs?

1. The control software has each phone click an ad link, download and open the app, move through a few screens and sometimes register an account.
2. The phone deletes the app, resets its advertising ID or does a factory reset so it looks like a new device.
3. It switches IP address through a proxy or a different SIM, then repeats.

How to detect and block phone farms

Common warning signs: an unusually high share of new devices, many installs from the same phone model and OS version, in-app steps that each take exactly the same amount of time, and day-7 retention close to zero.

On Android, the Play Integrity API has two signals suited to this problem. Recent device activity shows how many integrity tokens a device has requested in the last hour, with the highest level being more than 50 for standard requests (Android Developers, updated October 2026). Device recall (in beta) lets an app store 3 values on Google’s servers tied to each device, readable even after the app is reinstalled or the phone is factory reset (Android Developers, updated June 2026). On iOS, DeviceCheck lets you store 2 bits per device on Apple’s servers, for example to flag a device that has already claimed a promotion or has been marked as fraudulent (Apple Developer, accessed October 2026).

Example (hypothetical)

An e-wallet app gives 50,000 VND to each new account that links a bank account. One affiliate source brings in 3,000 installs in 5 days. 70% of them come from three old Android models, and only 2% are still opening the app on day 7. The app team turns on device recall to flag phones that have already received the reward, so repeat installs on the same phone after a factory reset don’t get paid a second time.

Frequently asked questions

Do MMP filters block phone farms?

Partly. MMPs filter by IP range, new-device density and behavior. Adding Play Integrity signals, DeviceCheck and the app’s own login data blocks more of it.

What’s the difference between a phone farm and a bot?

A bot is software that can run on a server or an emulator. A phone farm is real hardware running automated scripts, so it gets past device checks more easily but costs more to operate. Both are sources of install fraud.

If your new-user reward program is attracting a lot of fake accounts, take a look at Adtek’s App User Acquisition solution.