Jul 24th, 2009 | 1 Comment

Millions of Windows computers have been infected by a new computer worm dubbed “Conficker.” The situation is “not getting better,” but rather is “getting worse,” according to security software vendor F-Secure.

In a blog post, F-Secure security researchers report that the number of machines infected by the Downadup worm has skyrocketed from roughly 2.4 million to over 8.9 million in the last four days alone.

Downadup is a malicious worm that “uses computer or network resources to make complete copies of itself,” according to F-Secure. And it may also include code or other malware that damages both a computer and network. The worm also goes by the names “Kido” and “Conflicker.” Details on how it operates and how to remove it are here.

Once executed, Downadup disables a number of system services, including Windows Automatic Update, Windows Security Center, Windows Defender, and Windows Error Reporting. The worm then connects to a malicious server, where it downloads additional malware to install on the infected computer. Computerworld provides a more detailed report on Downadup’s potential dangers.

Since Downadup uses random extension names to avoid detection, Windows users should make sure their security software is set to scan all files, rather than checking on specific extensions, F-Secure recommends.

The alarmingly high number of Downadup infections led Microsoft last Tuesday to enable its anti-malware utility, Microsoft Software Removal Tool (MSRT), to detect the worm. So it’s important that Windows users, if they haven’t already, download the latest Microsoft security patch that went out earlier this week.

Written by Ajay Matharu

July 24th, 2009 at 9:34 am

Jul 13th, 2009 | No Comments

In Access, you can limit user entries by forcing users to choose a value from a list control. Office applications use the same functionality in built-in drop-down lists. For instance, the Highlight and Font Color controls on most Formatting toolbars use this flexible tool. Simply click the small triangle to the right of the icon to display a list of choices.

You can create the same type of control for your users in an Excel sheet, but the process isn’t intuitive. The option is in the Data Validation feature. Fortunately, once you know the feature exists, it’s easy to implement. You need only two things: a list and a data entry cell. The following sheet shows a simple drop-down list in an Excel sheet.

excel

Users click the drop-down arrow to display a list of items from A1:A4. If a user tries to enter something that isn’t in the list, Excel rejects the entry. To add this drop-down list to a sheet, do the following:

  1. Create the list in cells A1:A4. Similarly, you can enter the items in a single row, such as A1:D4.
  2. Select cell E3. (You can position the drop-down list in most any cell or even multiple cells.)
  3. Choose Validation from the Data menu.
  4. Choose List from the Allow option’s drop-down list. (See, they’re everywhere.)
  5. Click the Source control and drag to highlight the cells A1:A4. Alternately, simply enter the reference (=$A$1:$A$4).
  6. Make sure the In-Cell Dropdown option is checked. If you uncheck this option, Excel still forces users to enter only list values (A1:A4), but it won’t present a drop-down list.
  7. Click OK.

You can add the drop-down list to multiple cells. Select the range of data input cells (step 2) instead of a single cell. It even works for noncontiguous cells. Hold down the Shift key while you click the appropriate cells.

It’s worth noting that the drop-down arrow is visible only when the cell is active.

Written by Ajay Matharu

July 13th, 2009 at 9:27 pm