OfficePranks

Harmless PowerShell pranks for coworkers and friends who leave their computers unattended. Everything here is a joke — please keep contributions in that spirit. No malware, no data theft, no persistence beyond what a normal user can clean up in seconds.

Contents

File	What it does
CatFacts.ps1	Payload: ~18.75% of the time it raises the system volume and speaks a random fact from catfact.ninja via Windows speech synthesis.
Install-CatFacts.ps1	One-shot installer. Stages the payload, registers a Scheduled Task on a weekday work-hours schedule, and fires it once to verify.
Uninstall-CatFacts.ps1	Removes the task and the staged payload. Leaves git clones alone.

Quick install (one-liner)

Open PowerShell on the target machine and paste:

iex (irm https://raw.githubusercontent.com/TX-RX/OfficePranks/main/Install-CatFacts.ps1)

That downloads Install-CatFacts.ps1, which then downloads CatFacts.ps1 into %LOCALAPPDATA%\OfficePranks\, registers a Scheduled Task running every 30 minutes on weekdays 9 AM – 5 PM, and speaks one fact immediately so you know it worked. No administrator privileges required — everything runs in the current user's context.

Manual install

If you'd rather see what you're running before you run it:

git clone https://github.com/TX-RX/OfficePranks.git
cd OfficePranks
.\Install-CatFacts.ps1

When Install-CatFacts.ps1 finds a CatFacts.ps1 next to itself (i.e. you're running it from a clone), it uses that file in place instead of downloading. Edit CatFacts.ps1 first if you want to customize the speech, the volume, or the random gate.

Customizing the schedule

Install-CatFacts.ps1 exposes parameters for tweaking the cadence:

# Every 15 minutes from 8 AM to 6 PM
.\Install-CatFacts.ps1 -StartTime 08:00 -EndTime 18:00 -IntervalMinutes 15

# Use a fork instead of TX-RX/OfficePranks
.\Install-CatFacts.ps1 -SourceUrl 'https://raw.githubusercontent.com/<you>/OfficePranks/main/CatFacts.ps1'

# Skip the verification run at the end (silent install)
.\Install-CatFacts.ps1 -SkipVerifyRun

Full parameter list:

Parameter	Default	Purpose
-TaskName	OfficePranks-CatFacts	Scheduled Task name. Change it if you're stacking multiple pranks.
-SourceUrl	…/TX-RX/OfficePranks/main/CatFacts.ps1	Where to download CatFacts.ps1 when not running from a clone.
-StartTime	09:00	First fire of the day.
-EndTime	17:00	Last fire of the day.
-IntervalMinutes	30	Gap between fires.
-SkipVerifyRun	(off)	Don't speak a fact at the end of install.

Testing the payload

CatFacts.ps1 accepts a -Force switch that bypasses the random gate, useful for verifying audio works:

.\CatFacts.ps1 -Force

Uninstall

One-liner (mirror of the install)

iex (irm https://raw.githubusercontent.com/TX-RX/OfficePranks/main/Uninstall-CatFacts.ps1)

From a clone

.\Uninstall-CatFacts.ps1

Fully manual (if both scripts are gone)

Unregister-ScheduledTask -TaskName 'OfficePranks-CatFacts' -Confirm:$false
Remove-Item "$env:LOCALAPPDATA\OfficePranks" -Recurse -Force

The uninstaller is safe to run on a machine that was never installed — it just reports "not found" and exits. It also detects when %LOCALAPPDATA%\OfficePranks is actually a git clone (.git folder present) and leaves the directory intact in that case.

How it works

1. Random gate. On each run, CatFacts.ps1 rolls Get-Random -Maximum 10000 and only proceeds if the result is under 1875 (~18.75%). With a 30-minute trigger over an 8-hour day that's 16 chances per day, yielding ~3 expected fact deliveries.
2. Volume. Before speaking, the script sends the volume-down key 50 times to floor the system volume, then volume-up N times to set a known level (default 10, i.e. ~20% on a 50-step scale). This guarantees the fact is audible regardless of what the victim had set, including a muted machine.
3. Speech. Uses System.Speech.Synthesis.SpeechSynthesizer — built into Windows, no extra packages required.
4. Scheduled Task. Registered under the current user with LogonType Interactive and RunLevel Limited, weekly trigger on Mon–Fri with sub-trigger repetition every IntervalMinutes minutes for the duration EndTime - StartTime. No admin elevation, no system-wide changes.
5. Failure modes. If catfact.ninja is unreachable, the payload silently returns (try/catch around the API call) and waits for the next tick. If the speech subsystem isn't available, the script errors silently inside the hidden PowerShell window.

Safety notes

• This is intended for personal machines or shared dev boxes among friends. Don't deploy on company-managed devices without checking your acceptable-use policy — a hidden scheduled task that downloads and executes code is the kind of thing modern EDR products will flag, and rightly so.
• The volume override is the rudest part. If you want a kinder version, replace Set-Speaker -Volume 10 in CatFacts.ps1 with code that snapshots and restores the prior volume.
• All persistence is contained in one Scheduled Task and one folder. Nothing is written to the registry, no services are installed, no startup entries are created.

Contributing

Pull requests welcome for new pranks in the same spirit:

• Harmless and reversible — your prank must come with a one-step uninstall.
• No exfiltration. No data leaves the victim's machine except for benign public-API calls like catfact.ninja.
• No privilege escalation. Anything that needs admin is out of scope.
• No detection evasion beyond -WindowStyle Hidden on the scheduled action.
• Include Install-*.ps1 and Uninstall-*.ps1 scripts for each new payload, and update the README.

License

MIT.