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Colasoft just released a major upgrade of Capsa Network Analyzer a few days ago and we notice that the Security Analysis Profile is the most important new feature in Capsa 7.3 which helps users to locate and troubleshoot network issues and attacks like ARP attack, DoS attack and port scanning. Besides that, the feature of email auto-saving that users appreciated in previous versions had some adjustments. So, this article is aims to teach you how to save monitored email contents.

In Capsa Network Analyzer 7.3, if you need to save a copy of the monitored email to your hard disk, you should do the following:

Step 1. Enable Log Output

a. Go to the Start Page and click the Set Data Storage link on the right panel.
b. You see the Data Storage Options dialog box, highlight the Log Output tab and then check the Save log to disk checkbox.
c. Finish the settings of choosing file folder and setting up the rules to save logs in different files.

Step 2. Enable Email Copy

a. Double-click the analysis profile you want to use and enable the Email analysis module. Probably you’ll use Full Analysis or Email Analysis because they initially enabled the Email analysis module. This step is very important and if you don’t enable Email analysis module, Capsa will not analyze and capture any email.
b. Click Next and click Log Settings. You will focus on the Output Settings and make sure the Email Copy item is checked.

Set up as the instructions above, Capsa will save all captured inbound and outbound email contents to your hard disk. Why did you make these adjustments, you may ask? This is because users of the earlier versions might be toggled among different analysis profiles and they often forget to enable log output on different profiles. That means in previous versions, every analysis profile has a switch of email auto-saving. Therefore this time we can see the switch is made globally. Once you enabled log output, the logs will be saved to your hard disk no matter which analysis profile you choose.

It’s also notable that this time Capsa is able to output logs in multiple files as the rules you set. For example, you can set to save logs to a separate file every 10 minutes. It makes it easy for you to find useful logs in time-split small files rather than in a big log file.

I’m sure you already know how to save emails with Capsa 7.3 after reading through this article.

There comes the moment when the local network becomes very slow and they are suspicious of downloading in their network. To ensure the normal use of bandwidth, they need to find out who’s downloading in the network quickly and stop them to make sure everyone can work with efficiency. But many just don’t know how where to get started.

With Capsa Network Analyzer, you can find out the downloading computers within five minutes. Capsa captures all the traffics in the network, going-in and coming-out, and analyzes them to provide you enough statistics of the traffic. To find out who is downloading, we always start from looking into traffic volume of each machine.
Why should we start from traffic volume? That’s because when the downloading is digesting your bandwidth greedily, they will always generate greater traffic volume, not packets but bytes number.

Step1. Run Capsa, using Full Analysis with no filter, and capture traffic for three minutes.
Step2. Highlight IP Explorer -> Local Subnet in Node Explorer window.

Step3. Open the IP Endpoint tab in the Main View.Click Bytes column header to rearrange the list in DESC order.

The IP addresses with the longest bars on the top of the list are the suspects. But we need to eliminate the ones we trust. Then, we locate the machines with their IP addresses and warn them to stop downloading right away. It takes no more than five minutes and really it’s simple, right?

This article focuses on normal downloading, while there is another kind of downloading, Bit Torrent, out there. If you are interested about finding out Bit Torrent downloading in your network, please refer to here.

In networking, an email worm is a computer worm which can copy itself to the shared folder in system. And it will keep sending infected emails to stochastic email addresses. In this way, it spreads fast via SMTP mail servers. An email worm can send lots of infected emails in a very short time and it will never stop unless it’s removed. It will cause a large traffic and make the system go slowly. Sometimes it even makes the mail server crash. This article aims to teach you how to detect an email worm with Capsa network analyzer 7.

About Capsa 7

Capsa 7 is the flagship product of Colasoft. It is based on the second-generation Colasoft Packet Analysis Engine (CSPAE), which substantially improved the data processing speed and guaranteed the analysis performance in large traffic networks. Some unique features and ideas are introduced to Capsa 7, like Network Profile, this function allows user to set and save network profiles for different environments (departments, clients), making their analysis more customized, accurate and efficient. Another prominent feature is Analysis Profile which provides flexible, extensible and effective analysis performance based on user’s analysis objectives.

Step 1 of detecting an email worm with Capsa network analyzer 7: Diagnosis tab

In the Diagnosis tab we can see all the network issues automatically detected by Capsa network analyzer 7 , also some causes and solutions are suggested.

If there is a host infected with an email worm, we should be able to see SMTP events in the application layer like this:


Step 2 of detecting an email worm with Capsa network analyzer 7: Locate the source IP

Possibly the source IP is the host infected with an email worm as it is sending too many emails in a short period of time with SMTP. So let’s locate the source IP in the Node Explorer window with the Locate shortcut in the right-click menu.

Step 3 of detecting an email worm with Capsa network analyzer 7: Log tab

Check if the host is sending emails to a large number of recipients in a very short period of time. If so, we can determine the host is infected with an email worm and should be handled immediately. We should be able to see logs in the tab like this:

No doubt the final step is to isolate the host and kill the email worm with some AV software.So, I’m sure you already got how to detect an email worm with Capsa network analyzer 7. A free trail of Capsa network analyzer 7 is avaliable at http://www.colasoft.com/.

ARP attacks also known as ARP spoofing is a technique used to attack an Ethernet wired or wireless network. It is becoming increasingly popular among internet raggers because of its simpleness, fastness, and effectiveness, thus causing severe influence to the internet environment. As more and more people trust windows 7, it is very important to find a network analyzer that supports windows 7. Capsa network analyzer is such a great software that supports windows 7. The purpose of this article is to teach you how to detect ARP attacks in windows 7 with Capsa network analyzer.

The main point of ARP attacks detection is to locate the source of the attack when there is any ARP attack happens to our network. Capsa network analyzer can do it quickly and accurately. First of all, you need to download Capsa network analyzer at its official site and install it correctly. Now let’s see how we can achieve that.

Solution 1 to detect ARP attacks: Diagnosis Tab

The Diagnosis tab is the most direct and effective place we check the location of ARP attack, and should be our first choice.

Solution 2 to detect ARP attacks: Protocol Tab

As shown in the following figure, the status of ARP packets are displayed in the Protocol tab, Here we must pay special attention to the value of ARP Request and ARP Response. The ratio of ARP Request and ARP Request should be approximately 1:1 under general condition. If there is a great difference between these two values, there may be ARP attacks in the network.

Solution 3 to detect ARP attacks: Packet Tab

Packet decoding information in the Packet tab can tell us the original information of ARP packets, by decoding ARP packets, we can find out the source and destination of the ARP packets, the function and the reality of these ARP packets.

Solution 4 to detect ARP attacks: Physical Endpoint Tab

In the Physical Endpoints tab we can view the correlation of MAC address and IP address. Generally speaking, one MAC address shall have only one IP address corresponding to it. If one MAC address has multiple IP addresses to it, the condition may be:

1.the host with the MAC address is the gateway;
2.these IP addresses are bound to the MAC address manually;
3.ARP attack

Soluton 5 to detect ARP attacks: Matrix Tab

The Matrix tab allows us to see communication information between those hosts in the network, which helps us to fast identify abnormal conditions and locate the attack source.

From the above 5 solutions on how to detect ARP attack in windows 7 with Capsa network analyzer, it will greatly enhance network administrators’ capability to identify ARP attacks and protect the network from ARP attacks, so as to ensure normal network operation.

Network traffic is data in a network. In computer networks, the data is encapsulated in packets. So network traffic monitoring is to capture all the packets going down the network. Sometimes, it will be very useful to check your network activity. When Windows 7 network is very slow, internet browsing is very slow, connection problems and high network activity occurs when you do nothing, you will find this really helpful. The purpose of this article is to help you understand how to monitor network traffic in windows 7 with Capsa network analyzer.

About Capsa Network Analyzer

Capsa is an easy-to-use Ethernet packet sniffer (network analyzer or network sniffer) for network traffic monitoring and troubleshooting purposes. It performs real-time packet capturing, 24/7 network monitoring, reliable network forensics, advanced protocol analyzing, in-depth packet decoding, and automatic expert diagnosing. By giving you insights into all of your network’s operations, Capsa makes it easy to isolate and solve network problems, identify network bottleneck and bandwidth use, and detect network vulnerabilities.

Solution 1. Monitor network traffic in the Dashboard tab of Capsa network analyzer

If we want to have a graphical view of the statistics or get a trend chart of the network traffic, then we can use the graphs in the Dashboard tab. It provides a great many of statistic graphs from global network to a specific node. You are able to as well create almost any kind of graph based on any MAC address, IP address and protocol, etc. With these graphs, you can easily find out anomalies of the network and get useful statistics.

Solution 2. Monitor network traffic in the Summary tab of Capsa network analyzer

The Summary tab provides general information of the entire network or the selected node in the Node Explorer window. In the Summary tab we can get a quick view of the total traffic, real-time traffic, broadcast traffic, multicast traffic and so on. When we switch among the node in the Node Explorer window, corresponding traffic information will be provided.

Solution 3. Monitor network traffic in the Physical Endpoint and IP Endpoint tabs of Capsa network analyzer

In these two endpoint tabs (Physical Endpoint and IP Endpoint), we can monitor network traffic information of each physical address node and IP address node, both local and remote. With their easy sorting feature we can easily find out the nodes with abnormal traffic, such as which hosts are generating or have generated the largest traffic.

Solution 4. Monitor network traffic in the Protocol tab of Capsa network analyzer

The Protocol tab lists all protocols applied in your network transmission. In the Protocol tab we can monitor network traffic by each protocol. By analyzing the protocols in the network traffic, we can easily understand what applications are consuming the network bandwidth, for example, the HTTP stands for website browsing, and the POP3 stands for email, etc.

Solution 5. Monitor network traffic in the Matrix tab of Capsa network analyzer

The Matrix tab visualizes all network connections and traffic details in one single graph. The weight of the lines between the nodes indicates the traffic volume and the color indicates the status. As we move the cursor on a specific node, network traffic details of the node will be provided.

These are the very basic methods of monitoring network traffic in windows 7 with Capsa network analyzer, there are lot of advanced functions available on Capsa Network Analyzer 7 .

Share your experience with this tool and any new findings on this is welcomed.

The latest released Capsa Network Analyzer 7.2 supports monitoring instant message activity, which not only gives us real time monitoring, but also auto-saving instant messages details to local disk. Whether a parent who has teenager kid, monitoring his teenager kids’ online activities like whom are they chatting with, what they are talking about are of great importance to make sure the kids are safe and will not be misled. Or a company policy requires taking some measures to guarantee the employees’ working efficiency, one of the measures is to find out who is chatting on MSN or Yahoo Messenger about some non-working stuffs. This article is to talk about how to monitor instant message activities with Capsa 7.2 as well as save the messages to local disk.

To monitor instant messages, we need first to enable the IM analysis modules in the analysis profiles, because none of them are enabled by double-clicking an analysis profile to change the profile settings.

If we’d like to create a new analysis profile only used to monitor IM messages. Right-click anywhere in this section, and choose New from the context menu and only enable the MSN and Yahoo analysis modules.

Then click Next and then OK to finish the settings. Now click the big run button to start a capture.

When the main program is initiated and we go to the Log tab which holds the IM monitor results. In this tab, we’ll see two IM logs, MSN log and Yahoo log, including the time, sender’s account and the receiver’s account.

Not only can Capsa monitor all IM activities in our network segment, but also save these records to a csv file. Click the Export icon, and give the file a name. We can open the csv file with Excel to make a deeper analysis.

Someone may ask what if we are not around, is Capsa able to auto save the messages down to a file? Sure it is. Click the Log Settings icon, and click the Save Log File button. A new dialog box appears. Check Save to disk. There are two ways to save logs: save to a Single File and save to Multiple Files. For example, we enter the prefix for their name. And then decide how to split logs, say we split by everyone day. If we just want to save the latest files, we should check this and enter a number, say 30. We can read that we save everyday’s messages into a file, and just keep the latest 30. We’ll get the messages of the past 30 days. Now, any message goes from or to your network will be logged into a log file.

This is how Capsa monitors instant message activity and auto-saving the content to local disk. Hope it helps. And we have a video tuterial at our official site.

To football fans, today is a big day! FIFA World Cup opens today, Friday, June 11, 2010. They will spend the nights with the TV and bears. But our network admins will be drove crazy too. Why? The World Cup brings us great joys as well as certain network problems. Some of the crazy fans will watch or replay the competitions online at work. In these days, you will find your network traffic grows dramatically. I don’t want to be mean with the big fans, but we still have to do our work to maintain the network goes smoothly. How can we figure who is watching World Cup online at workplace? With Capsa network analyzer at hand, that would be so easy for you to monitor network, and prevent the network problems that World Cup may bring to your LAN.

Well, first we should make a list of football fans’ names and inform them not to watch videos online. And then we will keep an eye on our network utilization. When the utilization graph is high pitch, we know someone is disobeying the rules. Then we can check out who is consuming the bandwidth in the IP Endpoint tab.

But utilization cannot tell everything. We still need to spend a little seconds to check the protocols used in the network (Protocol tab). Special attention should be paid to protocols like P2P, RSTP and even HTTP. Online video takes a big portion of bandwidth so that we can easily find them out in the Protocol tab. The following figure shows that the HTTP traffic is abnormal which takes too much traffic.

When a suspicious protocol spotted, we should concentrate on it and check which IP address is generating the traffic in the IP Endpoint tab (figure below).

Then we could take a further step to prove our analysis. We can check out their conversations (IP Conversation tab), communication matrix (Matrix tab), and even we can go down to their original traffic packets (Packet tab).

With the above tips, I’m sure you can guarantee a healthy network during the special World Cup time.

We provide some tips on monitorring FBHOLE worm. In this article, we specificlly provide a step by step guide on how to build a fileter and monitor FBHOLE worm with Capsa network analyzer.

1. On the Start Page, click Packet Filter Settings link to open the Filter dialog box, which organizes all the filters.

2. Click the Add button (on the bottom-left corner of the dialog box) to build a new filter.

3.In the new window, choose Advanced Filter tab. And click the And icon. Choose Content from the context menu.

4. In the Pattern Rule window, just enter keyword: fbhole.com in the Pattern text box. Then click OK to close the window.

5. Click OK again to close the Packet Filter window.

6. Check the Accept checkbox of the filter just built which enables the program only capture the packets containing keyword “fbhole.com”.

7. Click OK and then start a capture.

8. If there is already a project running, you’d better stop it to build the filter and restart the capture. To build a filter in a running project: click the Filter button on the Ribbon. You will also see the Filter dialog box as well.

Facebook users have to be very careful when they’re hanging out on Facebook because a new worm called FBHOLE is out there everywhere. According to the reports that FBHOLE “doesn’t seem to be doing anything else than posting a message to people’s Facebook walls”. As an innovative network security software provider, Colasoft responses to analyze the worm immediately and we do get some ideas to help keep our users away from FBHOLE worm.

Behavior Study

If you click any post link like: http://www.fbhole.com/omg/allow.php?s=a&r=[random number] (post name” try not to laugh xD”) on a post wall, you will probably be lead to a page like the figure below:

Figure 1: try not to laugh xD with a fbhole.com link

The web page pops up a message box tells that there are some errors. Of course you will click the OK button to close the dialog box readily. Once you click the OK button, you may find there is one more post submitted to your wall.

Figure 2: Error messages

After the study of the HTML and scripts of the web page, we find that wherever you click on this page, you will trigger a script that tries to submit the same post to your Facebook wall. All these are done by a hidden iframe showing below:

Figure 3: iFrame code

This iframe follows your mouse movements. Wherever you click on the page, you will always click the invisible “Publish” button.

Tips to keep your network away from FBHOLE worm:

Until now we find that is all it does without any further harm to your computer system. To help keep our users to away fromthis worm, we do have some suggestions:

1. Inform the users in your network not click any links shown in the Figure 1.
2. Set up a filter to monitor which users click these links.
3. Locate the computer and scan it with an anti-virus program because there are possibilities that the worm may evolve to infect the operation system.

Google announced last week that users can visit https://www.google.com to establish a secure connection for their searches, which Google says “helps protect your search terms and your search results pages from being intercepted by a third party on your network”.

In response to the worries that search terms are eavesdropped by third party on public Internet accesses, especially at public like WIFI hotspots at airport, Google offers a connection over HTTPS to protect your search terms been sniffed. The purpose of this article is to figure out how does the encrypted search connection work and see if it really protects you. As packets never lie, we will go down to the packet level to check the original traffic out. Let Capsa network analyzer to prove that. First let’s check out how the normal search goes.

Normal Google Search

First run Capsa Network Analyzer and start a capture, then visit http://www.google.com, enter the keyword Capsa, and click the Google Search button. Until now, we can clearly see a HTTP packet captured with the keyword “Capsa”. If in a public network, the hacker can easily get the GET request and figure out your search terms with little tricks.

And another important way to get your search terms is to get the packet of your clicking on a link in the search results, which contains the keywords too. In this case we will click the second link in the results. When we go back to the packets, we can see there are two DNS packets, a DNS query and a response, then three-way-handshake with www.colasoft.com. The fourth packet is a HTTP GET packet.

If you are interested in this GET packet, you will find a Referer string in it, which is pretty the same as the string in figure below.

Encrypted Google Search

After the normal search, we flush the DNS, start a new capture, and reopen the browser. This time we visit https://www.google.com, enter the same keyword “Capsa”, and click the Google Search button. The page loaded and we go back to the analyzer and find there are DNS packets and HTTPS packets, without any HTTP packets (figure E). As all transmissions are protected by SSL, we cannot find any search keyword in these packets, unless you have that power to decode them.

Then we click the same link over the returned search results, and we find there are two DNS packets too and three-way-handshake and then a HTTP GET packet to load the Colasoft page. We can check this packet and find there is not a Referer string (figure F) in it. As google’s explanation, they’ve stopped transferring this value to the clicked page to prevent keywords being tracked.

Google also pointed out that the encryption search only protects you from keywords tracking but the website you visit later could also be spotted because of you DNS queries. And that’s something they cannot do about. But that’s not the topic of this article. We can sure that the new HTTPS Google search does what it alleged (you can learn more Google SSL search from http://www.google.com/support/websearch/bin/answer.py?answer=173733&hl=en). Furthermore, the society is talking about the network security more and more these days. We should always pay attention to our communications on the Internet, emails, social media communications and passwords, and so on.