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ICMP or DNS Cache Poisoning Attack

Issue

Details

For more information about event names in the ESET firewall log, see the following ESET Knowledgebase article:

Solution

If the ESET firewall is detecting a threat to your system, create an exception for internal IP traffic. Run the DNS flush tool if the issue is not resolved.

Create an exception for internal IP traffic

  1. Determine if the IP address detected in the notification is a number that falls within the following range (where "x" is 0-255):
    • 172.16.x.x - 172.31.x.x
    • 192.168.x.x
    • 10.x.x.x
  2. If the IP address detected is within the safe range listed above, open the main program window of your ESET Windows product. Skip to step 4.

  3. If the IP address being detected as a threat is not within the safe range listed above, or there are no network peripherals currently in use on your network, the device being detected by the firewall is located on a public network and could be a threat to your system.

    See the ESET DNS-Flush tool section and use it to repair any files that may have been damaged by DNS cache poisoning.
     
  4. Press the F5 key on your keyboard to access Advanced setup.
     
  5. Click Firewall, expand Advanced and then click Edit next to Zones.

    Version 8.x: Expand Network Personal firewall and then click Rules and zones.
    In the Zone and rule editor pane, click Setup. Click to view a screenshot.

Figure 1-1

  1. In the Firewall zones window, select Trusted zone and click Edit.

    If you are running version 8.x: Click the Zones tab, select Addresses excluded from active protection (IDS) and then click Edit. Click to view a screenshot.

    In the Zone setup window, click Add IPv4 address. Click to view a screenshot.

Figure 1-2

  1. Type the IP address of the device being incorrectly detected as a threat in the Remote computer address (IPv4, IPv6, range, mask) field.

    If you are running version 8.x: Select Single address, and then enter the IP address of the device being incorrectly detected as a threat. Click to view a screenshot.

Figure 1-3

  1. Click OK three times to exit Advanced setup and save your changes. You should no longer see any messages about attacks coming from an internal IP address that you know to be safe. If you continue to experience this issue, proceed to solution 2 below.

    If you are running version 8.x: Click OK four times to exit the Advanced setup tree and save your changes.

Figure 1-4

Run the DNS Flush tool (DNS poisoning only)

You can use the ESET DNS Flush tool to flush your DNS cache. Follow the step-by-step instructions below to download and run the DNS Flush tool:

  1. Download the DNS-Flush.exe tool and save the file to your Desktop.
  2. Navigate to your Desktop and double-click DNS-Flush.exe (if you are prompted to continue, click Yes). The tool will automatically flush and register your DNS cache.
  3. After your computer restarts, open your ESET product and run a Computer scan. For assistance, refer to the following Knowledgebase article:

The Computer scan should finish without detecting an infection. If no threat is detected, you are finished.

If you are still unable to resolve your issue, please email ESET Technical Support.



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