CD library sorts evidence

 

Connecting state and local government leaders

Mark Weil's fingers have been ink-smeared for nearly four years from sorting through case files on everything from child exploitation and prostitution to computer security and e-mail threats.

Mark Weil's fingers have been ink-smeared for nearly four years from sorting through case files on everything from child exploitation and prostitution to computer security and e-mail threats.Weil, an examiner at the Defense Department's computer forensics lab, anxiously awaits the arrival this month of the first CD-ROM version of the National Software Reference Library. It profiles 652,000 common pieces of software and matches them against seized computer files to separate what's innocent from what might be criminal evidence.The National Institute of Standards and Technology compiled the database on CD-ROM for federal, state and local law enforcement users.The 125M database categorizes up to 100,000 file types in seconds so investigators do not have to open every one to look for evidence.'If you can eliminate 20,000 to 30,000, you reduce your workload by 20 to 30 percent, which is enormous,' Weil said.For work on time-sensitive cases, eliminating a hunt through thousands of files could be a significant time savings, said Barbara Guttman, a researcher in NIST's information technology lab who helped develop the database.'Sometimes you're do-ing it for a case where people are going to die,' Guttman said.Weil said he remembers having to open hundreds of files on a disk taken from a crime scene to see if any files were germane to the case.'The database is how we identify the irrelevant files,' Guttman said. Almost any file that matches up exactly with the NSRL hashing algorithms is not going to be evidence. Corrupted files that do not match the profiles, however, raise red flags.'The whole idea of this is to reduce the examiner's time,' said Susan Ballou, program manager of forensic science projects at NIST's Office of Law Enforcement Standards in Gaithersburg, Md.Examiners 'know what certain files look like and can just ignore them,' Ballou said.NSRL runs on any computer with standard database management software. It uses three algorithms: Secure Hash Algorithm 1, which computes a condensed representation of a message or a data file; two other algorithms called MD 4 and 5; and the CRC-32 checksum algorithm.Without the CD, investigators like Weil must spend hours or days comparing the seized file signatures to common templates for shrink-wrapped software.'It takes time to calculate the hash on each file,' Weil said. The NSRL software calculates the hash for him. If a particular hash from a file on a crime scene disk does not match any NSRL hash, he looks at it. 'Either we didn't get that legal software product on the NSRL, but it's still a legal file, or something on the disk has been altered,' Ballou said.Investigators can save lots of time by ignoring, for example, Microsoft Windows 2000 or Office 2000 files, which have well-known hashes, Weil said.To deal with new types of software, NSRL will come out in new versions each quarter. 'Each subsequent version should save the investigators time,' Guttman said.More often than not, investigators have to copy drives and disks found at a crime scene regardless of the kind of crime, Guttman said.'Sometimes it isn't a computer crime but the records are in the computer,' she said. 'If you're running an illegal gambling operation, you might store your books on the computer, and law enforcement wants to find those files.'The FBI and the Defense and Treasury Departments have paid their $90 annual subscriptions for the NSRL disk. The FBI will use NSRL in its Automated Computer Examination System suite.Guttman said she hopes the database will be useful for intellectual property crimes, too. 'Most everything is on computers now,' she said.

Mark Weil, a DOD computer forensics examiner, expects a NIST CD to save him time searching computers seized as evidence.

































Quarterly updates











NEXT STORY: CIOs search for prot'g's

X
This website uses cookies to enhance user experience and to analyze performance and traffic on our website. We also share information about your use of our site with our social media, advertising and analytics partners. Learn More / Do Not Sell My Personal Information
Accept Cookies
X
Cookie Preferences Cookie List

Do Not Sell My Personal Information

When you visit our website, we store cookies on your browser to collect information. The information collected might relate to you, your preferences or your device, and is mostly used to make the site work as you expect it to and to provide a more personalized web experience. However, you can choose not to allow certain types of cookies, which may impact your experience of the site and the services we are able to offer. Click on the different category headings to find out more and change our default settings according to your preference. You cannot opt-out of our First Party Strictly Necessary Cookies as they are deployed in order to ensure the proper functioning of our website (such as prompting the cookie banner and remembering your settings, to log into your account, to redirect you when you log out, etc.). For more information about the First and Third Party Cookies used please follow this link.

Allow All Cookies

Manage Consent Preferences

Strictly Necessary Cookies - Always Active

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data, Targeting & Social Media Cookies

Under the California Consumer Privacy Act, you have the right to opt-out of the sale of your personal information to third parties. These cookies collect information for analytics and to personalize your experience with targeted ads. You may exercise your right to opt out of the sale of personal information by using this toggle switch. If you opt out we will not be able to offer you personalised ads and will not hand over your personal information to any third parties. Additionally, you may contact our legal department for further clarification about your rights as a California consumer by using this Exercise My Rights link

If you have enabled privacy controls on your browser (such as a plugin), we have to take that as a valid request to opt-out. Therefore we would not be able to track your activity through the web. This may affect our ability to personalize ads according to your preferences.

Targeting cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

Social media cookies are set by a range of social media services that we have added to the site to enable you to share our content with your friends and networks. They are capable of tracking your browser across other sites and building up a profile of your interests. This may impact the content and messages you see on other websites you visit. If you do not allow these cookies you may not be able to use or see these sharing tools.

If you want to opt out of all of our lead reports and lists, please submit a privacy request at our Do Not Sell page.

Save Settings
Cookie Preferences Cookie List

Cookie List

A cookie is a small piece of data (text file) that a website – when visited by a user – asks your browser to store on your device in order to remember information about you, such as your language preference or login information. Those cookies are set by us and called first-party cookies. We also use third-party cookies – which are cookies from a domain different than the domain of the website you are visiting – for our advertising and marketing efforts. More specifically, we use cookies and other tracking technologies for the following purposes:

Strictly Necessary Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Functional Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Performance Cookies

We do not allow you to opt-out of our certain cookies, as they are necessary to ensure the proper functioning of our website (such as prompting our cookie banner and remembering your privacy choices) and/or to monitor site performance. These cookies are not used in a way that constitutes a “sale” of your data under the CCPA. You can set your browser to block or alert you about these cookies, but some parts of the site will not work as intended if you do so. You can usually find these settings in the Options or Preferences menu of your browser. Visit www.allaboutcookies.org to learn more.

Sale of Personal Data

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Social Media Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.

Targeting Cookies

We also use cookies to personalize your experience on our websites, including by determining the most relevant content and advertisements to show you, and to monitor site traffic and performance, so that we may improve our websites and your experience. You may opt out of our use of such cookies (and the associated “sale” of your Personal Information) by using this toggle switch. You will still see some advertising, regardless of your selection. Because we do not track you across different devices, browsers and GEMG properties, your selection will take effect only on this browser, this device and this website.