Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsiTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
Yes. TeamViewer said in May 2019 that attackers targeted its systems in autumn 2016. The company reported that it stopped the attack before major damage and that forensic investigators found no evidence of stolen customer data, infected customer computers, or compromised source code. Those are TeamViewer’s reported findings, not proof that impact was impossible.
What TeamViewer confirmed about the 2016 attack
In a statement quoted by BleepingComputer on May 20, 2019, TeamViewer said suspicious activity was detected in autumn 2016. The company said internal and external security experts worked with authorities and “successfully fended off the attack.”
TeamViewer said investigators found no evidence that customer data or other sensitive information had been stolen, that customer computers had been infected, or that TeamViewer source code had been manipulated, stolen, or misused. The company also said independent experts found no evidence that users’ security or IT systems had been affected. These statements describe what the company said its investigation found; they do not establish that an impact was impossible.
Free tools Windows power users keep installed
One-click scans. No signup required.
Why TeamViewer did not disclose it at the time
TeamViewer said it did not issue a public notice in 2016 because it and the responsible authorities and advisers concluded that disclosure was unnecessary and could hinder the investigation or prosecution. The company’s explanation was reported by SecurityWeek and BleepingComputer when the incident became public in 2019.
#1 Best Overall
- POWERFUL SECURITY KEY: The Security Key C NFC is the essential physical passkey for protecting your digital life from phishing attacks. It ensures only you can access your accounts.
- WORKS WITH 1000+ ACCOUNTS: Compatible with Google, Microsoft, and Apple. A single Security Key C NFC secures 100 of your favorite accounts, including email, password managers, and more.
- FAST & CONVENIENT LOGIN: Plug in your Security Key C NFC via USB-C and tap it, or tap it against your phone (NFC) to authenticate. No batteries, no internet connection, and no extra fees required.
- TRUSTED PASSKEY TECHNOLOGY: Uses the latest passkey standards (FIDO2/WebAuthn & FIDO U2F) but does not support One-Time Passwords. For complex needs, check out the YubiKey 5 Series.
- BUILT TO LAST: Made from tough, waterproof, and crush-resistant materials. Manufactured in Sweden and programmed in the USA with the highest security standards.
The June 2016 account takeovers were a different incident
Reports from June 2016 described unauthorized access to individual TeamViewer accounts, including user reports of financial abuse. Those reports came months before the autumn corporate attack later confirmed by TeamViewer. They should not be treated as evidence that the two incidents were the same.
At the time, TeamViewer denied that its systems had been breached and suggested password reuse or malware could explain the account abuse. A representative told Ars Technica that externally obtained credentials and reused passwords were a likely explanation. When asked about the number of abused accounts, the representative said there was no precise figure, only that it was significant. That account-takeover report does not provide a victim count for the later-disclosed corporate attack.
Rank #2
- POWERFUL SECURITY KEY: The YubiKey 5 NFC is the most versatile physical passkey, protecting your digital life from phishing attacks. It ensures only you can access your accounts
- WORKS WITH 1000+ ACCOUNTS: Compatible with popular accounts like Google, Microsoft, and Apple. A single YubiKey 5 NFC secures 100+ of your favorite accounts, including email, password managers, and more
- FAST & CONVENIENT LOGIN: Plug in your YubiKey 5 NFC via USB and tap it, or tap it against your phone (NFC), to authenticate. No batteries, no internet connection, and no extra fees required
- MOST SECURE PASSKEY: Supports FIDO2/WebAuthn, FIDO U2F, Yubico OTP, OATH-TOTP/HOTP, Smart card (PIV), and OpenPGP. That means it’s versatile, working almost anywhere you need it
- PRIMARY & SPARE KEYS: Just like having a spare house key, we recommend buying two YubiKeys - one for daily use and one as a spare. That way you’ll never get locked out of your accounts
Who was behind the autumn 2016 attack?
TeamViewer reportedly said there was strong evidence pointing to a China-linked actor, but the attribution was not certain. The available reporting does not establish that a specific named group was conclusively responsible, so the attack should not be attributed to one as fact.
How the 2024 TeamViewer incident differs
TeamViewer disclosed a separate corporate IT incident in 2024. Its security bulletin records detection on June 26 and the end of the main response phase on July 4, 2024. TeamViewer attributed that incident to APT29, also known as Midnight Blizzard, and said its investigation found the activity confined to corporate IT, with no impact to the product environment, connectivity platform, or customer data. That attribution and those findings concern the 2024 event, not the 2016 attack.
Quick Recap
Rank #4
- POWERFUL SECURITY KEY: The Security Key NFC is the essential physical passkey for protecting your digital life from phishing attacks. It ensures only you can access your accounts.
- WORKS WITH 1000+ ACCOUNTS: Compatible with Google, Microsoft, and Apple. A single Security Key NFC secures 100 of your favorite accounts, including email, password managers, and more.
- FAST & CONVENIENT LOGIN: Plug in your Security Key NFC via USB-A and tap it, or tap it against your phone (NFC) to authenticate. No batteries, no internet connection, and no extra fees required.
- TRUSTED PASSKEY TECHNOLOGY: Uses the latest passkey standards (FIDO2/WebAuthn & FIDO U2F) but does not support One-Time Passwords. For complex needs, check out the YubiKey 5 Series.
- BUILT TO LAST: Made from tough, waterproof, and crush-resistant materials. Manufactured in Sweden and programmed in the USA with the highest security standards.
Rank #3
- POWERFUL SECURITY KEY: The YubiKey 5C NFC is the most versatile physical passkey, protecting your digital life from phishing attacks. It ensures only you can access your accounts
- WORKS WITH 1000+ ACCOUNTS: Compatible with popular accounts like Google, Microsoft, and Apple. A single YubiKey 5C NFC secures 100+ of your favorite accounts, including email, password managers, and more
- FAST & CONVENIENT LOGIN: Plug in your YubiKey 5C NFC via USB and tap it, or tap it against your phone (NFC), to authenticate. No batteries, no internet connection, and no extra fees required
- MOST SECURE PASSKEY: Supports FIDO2/WebAuthn, FIDO U2F, Yubico OTP, OATH-TOTP/HOTP, Smart card (PIV), and OpenPGP. That means it’s versatile, working almost anywhere you need it
- PRIMARY & SPARE KEYS: Just like having a spare house key, we recommend buying two YubiKeys - one for daily use and one as a spare. That way you’ll never get locked out of your accounts
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
