Thursday, July 31, 2008

CbEvtSvc.exe Is Not Flash

We are researching a couple of highly prevalent pieces of malware, and may be drawing some links between the two.

Thousands of websites have been compromised and are spreading phony "get_flash_update.exe" files via a "showvideo.html" page titled "Watch Free Movie". But you won't be watching "Out of Africa" once this malware gets dropped on your system. This executable provides months old malicious functionality when, instead of updating flash, it drops "CbEvtSvc.exe" to the system directory and runs this trojan from there. Exploit pages that we've examined also deliver files with static names like "wXtwRzv.exe" and the slightly more camouflaged "C:/Documents and Settings/All Users/Start Menu/Programs/Startup/smss.exe".

Here is a list of google results for a search on showvideo.html. You'll see over one thousand hits (a german news agency reports 20,000 customers at one ISP effected). The compromised sites that we have evaluated in the lab appear to mostly be located in Europe, but they are scattered. They maintain the same executables, images, html and javascript exploit pages. DO NOT VISIT THESE LINKS. They will redirect to a 1.html exploit page containing multiple canned exploits that we are analyzing:



Clicking on one of these links takes the user to malicious sites presenting a page with an apparently persuasive social engineering scheme, enticing the user to run a flash update with a blank video mockup. A popup appears with "Flash player: Incorrect version":


When the user attempts to close the dialog box in front of them, the page takes another stab at prompting the user to run the install (statistics probably are in the bad guys favor here):



This sort of blended threat attack is somewhat like the Storm sites of last year, where the administrators of the malicious content attempt to con the user into manually running the malware if their drive-by exploits from 1.html fail in the browser background. The themes varied a bit more and were more creative than this one. So far, we've seen the following vulnerabilities targeted by canned exploits on these sites:
Old reliable MS06-014 MDAC Vulnerability (nothing new here)
The fresh new Microsoft Office Snapshot Viewer ActiveX control race condition
The one year old Online Media Technologies NCTsoft NCTAudioFile2 ActiveX buffer overflow
A one year old stack overflow in GomManager
The recent RealPlayer.Console heap vulnerability
The 2006 ancient WebViewFolderIcon.setSlice integer overflow vulnerability. Thanks HD, the gift keeps on giving.
The exploit page utilizes reliable heap spray techniques to deliver its standard download and exec shellcode for the overflow attempts.

We will continue to research this one and provide more details here. The interest here is mostly in the large scale effort to spread this months old malware and serve it up on newly compromised sites under a somewhat different name. The spam is mostly the same, as it has been spread as video.exe, video.avi.exe, and others.
Our hunch is that a IM worm or spammed link over the past several days was dropping an ftp password stealer that in turn collected the passwords to upload these "showvideo.html" pages and other content alongside the usual content to these legitimate sites. The sites continue to serve up legitimate pages as well. There were CuteFtp and other stealers, distributed in prevalence, with random names starting "wins.exe" over the past several days. The first of the suspected stealer family started with the name winsbb.exe.

In the meantime, if you need to update your Flash player, only do so at the legitimate Adobe site.

Thursday, July 24, 2008

DNS Cache Poisoning

A google search for poison still returns a top result for one of the tackiest 80s pouty lipped glam bands around. They are still on tour, and they probably haven't even heard of Dns.

Dns cache poisoning (there is a fine wiki for it) vulnerabilities have been all the rage on various security research mail lists for the past couple weeks and should be at the top of any search result list now. New working exploits targeting those vulnerabilities have been created and distributed. Coincidentally, Blackhat is being held next week, where Dan Kaminsky will present his original findings on it. Dan Kaminsky reportedly grouped together a huge number of dns providers and got a patch properly worked out and distributed for this thing.
What does "DNS Insufficient Socket Entropy Vulnerability" really mean to the average end user? Before you ask, there is a hitch. What was supposed to remain mysterious and closeted within the shadowy network security and dns administrator community has been released full force via full disclosure and Metasploit, the open source pen testing tool project run by HD Moore and friends. This addition means that this potentially dangerous information is public and potentially freely usable.
So now go ahead and ask. What does "DNS Insufficient Socket Entropy" really mean to me? If you are a standard user, you're probably not administering a Dns server, but you (possibly unknowingly) are using Dns. Your ISP maintains these DNS servers, or the routes to them, for you. It is these systems that tell your browser what server to connect with when you are visiting "www.google.com". They need to send your browser's requests to your bank's authentic web site when you attempt to browse it, instead of some creaky old mock up hosted in the furthest reaches of the planet. While you are dependent on Dns servers working properly and supporting "sufficient entropy", there most likely is nothing you directly can do to administer and patch them.

In the meantime, visit the Microsoft Update site to check for new updates and ensure that third party software on your system is patched. Dns admins need to get their servers patched.
You can check Dan Kaminsky's own site here or another tool here for information to present to your ISP, if they haven't yet patched.

Update: Dan Kaminsky posted additional information that "DNS clients are at risk, in certain circumstances", and that microsoft is patching multiple other dns client-side vuln ("has received two MSRC fixes in the past six months"). So, while the major focus is on the Dns servers, be sure to visit the windowsupdate site and patch away!

Wednesday, July 23, 2008

Better Behavioral Detection

Talented and well connected cyberthreat analyst Dancho Danchev posted an interview with researcher Thierry Zoller of n.runs AG, the group that recently published a paper on 800 AV product vulnerabilities. He gave Thierry a chance to discuss thoughts on McAfee's response to the vulnerability findings.
Keep in mind, I may be a bit biased that ThreatFire is one of the best behavioral based products out there, and here is my favorite part of the interview:

"Dancho : Isn’t the single most important vulnerability found in antivirus software during the last couple of years, the easy to bypass signatures based scanning approach, and the product concept myopia of spending years of research into heuristics where the same amount of resources should have probably been spend on behavioral detection solutions?

Thierry : From a larger viewpoint, concentrating the functional aspect of AV software - you are absolutely correct. The “problem” with behavioral detection is this one - they need less updates and..updates is what keeps the AV business model rolling. If this would have not been the case - I am sure we would have a lot better behavioral and overall detection nowadays. It’s ridicule how easy it is to bypass heuristics."

Great reading.

Monday, July 21, 2008

Whitelists Killed AV?

c|Net writer Robert Vamosi posted some pretty fascinating insights into the future of the AV industry on his "Defense in Depth" column. He begins with some alarming-sounding criticism of the products: "I've been hearing some well-regarded security people tell me they are considering ditching their antivirus protection all together."
But this grumbling from the security community always has been present. In part, it seems to be jealousy at the financial success of the top players in this security industry, and partly it seems to be insightful and constructive criticism towards the level of effectiveness and the level of insecurity that dependence on these applications brings. "Right click on signature updates" does not mean one's computer is secure.

The blog that you are reading is full of screenshots and messages regarding AV scanner misses (false negatives). Often, these misses are just plain shameful. There are AV scanners that even have failed the most minimal testing when they miss samples from the WildList (the WildList is not Dead!). And often, at a practical level, some of the misses are understandable, and somewhat expected.

However, this information does not mean that AV scanners will disappear altogether. But it's interesting to read about how much spin some of the players are putting on whitelisting, which already is something that is performed on a selective basis in a number of products. Users just never read much about it because it was seen as a weakness in scanning products. In a meeting once, an employee of one of the large vendors exclaimed "our scanner is like a laser! It's precise, like a laser!" Which in fact, wasn't really true at the time, but that's beside the point. The point is that scanners were expected to exploit their strength, which was to identify file content precisely with an extremely low incidence of false positives.
So to deal with that stigma but still make progress with improving their products, it seems that the largest vendors are embracing just the thing that they have fought against in the past -- the impression that they need to rely on whitelisting:
"That's why vendors are talking to me about newer strategies for 2009 (and beyond). Among these is the exact opposite of signature file databases--something called whitelisting."
(Btw, this statement doesn't seem to make sense. Whitelisting is in fact a signature file database. It is simply a database of non-malicious files, however the vendor wants to store or distribute it.)

Nonetheless, to me, and Vamosi's article, all this whitelist talk doesn't mean the end of AV. It means that the vendors are publicly embracing what was once seen as a weakness. It seems to me that no matter how talked up whitelisting is at this point, AV scanners will not be uninstalled. Rather, they will be a less costly layer in any security solution, alongside more exposed whitelisting components.
So, will you be ditching your antivirus application anytime soon? Perhaps you'll ditch a standalone product, but you most likely will be installing the same technology in a different package over the next couple of years.

Friday, July 18, 2008

Can't Create a Rule

The "Rogue" computer engineer from San Francisco that granted himself exclusive administrative access, at the very least locking out admin access from other users, to a city network housing confidential city records still is in jail on $5 million bail. Earlier today, he pleaded not guilty to four counts of computer tampering. Strangely, the city still seems to be waiting for the password.

We can deal with Rogueware, or Rogue AntiSpyware. But sorry, we can't add a rule for this sort of behavior.

Wednesday, July 16, 2008

IRS Stimulus Payment Scam Continues

The IRS warned users of fraudulent emails that request users visit a web site and disclose personal information. Here is a screenshot of a version of the scam we just received:



Notice that the "Click here" link provides a non-IRS link (the ads.lynchburg.net-redirected website is now down), which redirects to a server in the .de domain (in Germany). The stimulus payment logo is linked directly to the irs site, however, making the email itself look official. This email is another example of carefully crafted "phish".

Always take careful consideration when reviewing email requesting sensitive information from you.

Tuesday, July 15, 2008

Posing as Microsoft Deliverables

Another Fakealert variant resorts to displaying a set of deceptive messages that can be found within the executable, while disguising the file as a Microsoft deliverable. These deceptions are best described as "cheap". Don't fall for it.

Here is a screenshot of the file properties from "uoyzsydz.exe", a file that attempts to open a browser on a victim's system to download more shocking fakealert ad content. Notice the use of the phony Microsoft trademark, the techie-sounding file description "Parsing software fo XML Media", and the official update-sounding version "2.34.0.1016":



At the time users were receiving and running the fresh new round of these released binaries, AV scanner detection was mostly non-existent, as it is missing for most of these new releases.

Unlike the xml parsers that Microsoft actually delivers, this module is packed simply with UPX and maintains fraudulent "shocker" strings to display to the user:
"Windows has detected spyware infection on your PC"
"Slow operation speed might have been caused by spyware."
"Internet attack detected."
"Somebody's trying to infect your PC with spyware or harmful viruses."
"Your computer is not protected against spyware."
"Spyware has been detected on your computer! Click here to run a FULL SYSTEM SCAN to protect your data"
"VERY HIGH RISK [ 5 / 5 ]".

It's not a surprise that no strings for "LOW RISK [ 1 / 5 ], DON'T BOTHER SHELLING OUT HARD EARNED MONEY BECAUSE OF OUR FRAUDLENT CLAIMS" appear anywhere in this file.

QQ Updates on Dns Port over Http?

Usually, port 53 is used for DNS queries and transactions over both tcp and udp, while http GET request traffic is handled over tcp 80 or 8080 (or ssl encrypted over 443).

Instead, currently we have an unusual set of files, often named "qq_updates.cab" that are being renamed and run on a fairly high number of user systems (they are not cab files. They are malicious executables) and querying http servers hosted in China over tcp port 53 for gif files (1.gif, 2.gif, 3.gif, B.gif, c.gif, etc). These queries are not standard dns lookup requests as a network admin might expect, or standard http requests for image files.

The responses for these gif file requests are either location information and directions to download more spyware executables or are additional spyware executables themselves, designed to steal a user names and passwords from multiple gaming applications. Some of the writers are becoming more clever and using encoded data over that port as well. Prevalence is high, and network admins may want to monitor dns ports for unusual http traffic for .gif files carrying nothing but executable content.

Tuesday, July 8, 2008

Greetings

Kill the messenger? In this case, yes.

A round of "hallmark.exe" files are being downloaded and run by some of our community. Some pop images of pleasant scenes like strangely named "xmas.jpg", which doesn't look much like xmas anywhere to me:


In the background, however, this hallmark greeting is unpleasantly dropping and installing multiple IRCbot components. It copies out what looks like a common windows system file "spoolsv.exe" to windows\temp\spoolsv, but it really is a common IRC application. Multiple other configuration files are copied out so that the application connects back to the common IRC port 6667 on a number of undernet.org and servebeer.com sites for further instruction.

On its own, the mIRC application provides plenty of legitimate uses. But when packaged up and performing unexpected actions, this app can be severely misused.

As always, stay wary of links that are sent to you via email.


Note: these types of emails are arriving with varying flavors. This one is definitely related to the recent 4th of July "july.exe" IRCbot variants that were sent out and mistakenly associated with the Storm gang by some of the research community.

Saturday, July 5, 2008

AMTSO Progress

PC Tools is proud to be a participating member of The Anti-Malware Testing Standards Organization (AMTSO). The group recently met to discuss (argue) over details of proposed standards in Washington on the Microsoft Campus, and we look forward to eventual formal completion and public release of these standards.

We had a great accommodations on the trip. Great room number. :)


Thursday, July 3, 2008

Return of Rustock?

Return is a powerful concept in many ways. In literature, return can touch on the limits of faith, love, loyalty, friendship, fidelity and mortality.

Homer's Ulysses wanders for years, returning to his home and his family in disarray. Initially, the only witness to recognize Ulysses in his home is his old dog Argus, faithfully waiting for his master's return over those 20 years: "As soon as he saw Odysseus standing there, he dropped his ears and wagged his tail, but he could not get close up to his master. When Odysseus saw the dog on the other side of the yard, dashed a tear from his eyes...But Argos passed into the darkness of death, now that he had seen his master once more."

Edward Fitzgerald's "The Rubaiyat of Omar Khayyam" speculates on the importance of understanding the inability to return:
"Then to the lip of this poor earthen Urn
I lean'd, the Secret of my Life to learn:
And Lip to Lip it mumur'd -- "While you live
Drink! -- for, once dead, you never shall return"

Unfortunately, in our last round of spambots, we find lots of return. However, these returns do not provide deep insight or wistful second comings. Instead, these returns serve to obfuscate the functionality of the rootkit driver component ("pgasghjd.sys") that appears to be the newest project of one of the rustock creators:
C:\progz\NewWork2\driver\objfre\i386\driver.pdb

Return is a powerful computing concept, and an important part of any CPU instruction set. The "RET" or "Return from procedure" instruction "transfers control to a return address located on the top of the stack".
These returns are used in an unusual way in the unpacking stub of the driver, avoiding making standard calls early in the routine. Here is the driver's entry point.



Notice the push of a hard-coded offset and the immediate return. This unusual sequence of assembly instructions simply pushes a return address to the stack, only to take control when the "ret" or "retn" is executed and control flows to this new offset. This sequence can be used as an effective emulator evasion trick.

These returns do not provide anything all that valuable, instead, these returns help to produce the unwanted spam, clogging global network pipes and peddling "male enhancement" drugs. These are the messages that are crass and vain, including with them a link to a couple of these "drug" peddling web sites. Obscene messages are not reproduced here, but here are a few examples:
"Give your chick a night to remember"
"Make sure you don't get left out of the action at parties"
"Fantastic results guaranteed"

Some returns come with really bad literature.

Tuesday, July 1, 2008

Lousy Storm Distribution

Our users in the Czech Republic are the first to see email spam, and download and run the newest executable from the Storm campaigns.

If you arrive at a web site with "Who is loving you? Do you want to know?", offering up "mylove.exe", ignore it. Don't run the file, which immediately copies "msvecurity.exe" to the windows directory, and works its standard p2p magic from there.

Interesting to note that it connects back to a chinese server on cadeaux-avenue.cn for config information.

The Future is Now

It is the distant year 2000.

There is no more unhappiness. There is only one kind of dance. You no longer say yes, except in colloquial situations. Computer security seems to have failed the humans.


Never trust a robot.

New Undetected Worm

We're seeing a new version of the worms that we previously posted info about.

Some slight changes in the newest version: circulating with the name "newphoto011.jpeg-www.myspace.com", which I'm sure will change soon enough. This time, it hides a new process that loads "msnp2pmgr.exe". The authors keenly call it their "MSN P2P Manager". It connects back to xili.zerolost.org, hosted at a number of ip's...Addresses: 64.34.203.207, 66.135.32.35, 195.137.213.67, 195.149.74.40, 195.149.74.67, 64.34.161.89, 64.34.202.227.


The authors seem to be getting a bit more aggressive against security solutions, delivering a long list of modifications to the hosts file with their worm that can be seen on this ThreatExpert report (look to the bottom of the report under "The HOSTS file was updated with the following URL-to-IP mappings"). These modifications prevent a user from visiting sites that may describe this worm as malicious, and also block security solutions from downloading signature updates as well.


AV scanner detection catching up: