Day by day… | forensics

Darkleech – malicious Apache mod anti-forensics – client-side.

2013.03.18

I wrote about Darkleech last year, and one of questions remain - among anti-forensics features of it, that seller declared, were:

- frame delivered to unique users only, no frame on repeat.

So – How it looks like for victim and how implemented?

Since than Linux/Chapro.A was posted in SecLists and analysed by Kaspersky and ESET.

Afterwards Eric Romang provided some details, that it appear to be version of Darkleech module.

And here it appear again: UnixFreaxJP blog report about massive attack on Japanese segment of Internet.

Well, It’s time to see, is it DarkLeech and how anti-forensics implemented there from client PoV

Ok. Let’s see on any of servers that in list:

Cool Exploit Kit – “We Try harder!”

2013.03.13

Heh, when I am sick – it’s time to hunt…

Prerequisites:

Temperature: 37.8 C

Local Time: 23:00

Mood: [censored]

Test machine: fully updated (pdf, flash, java up to 7.u17)

Live Exploit Kits in list: 5

What we testing:

How dangerous can be surfing for those who follow best practices – at least performing updates.

Results:

All behavior among tested Exploit Kits, can be described as:

- If plugin-detect present, than system realize that no vulnerable plugins detected, and

- no exploit served at all [Safe End]

- last available Java exploit served. [Fail]

- If plugin-detect not present, than all available exploits execute and fail.

* Sometimes LibTiff exploit crash the PDF plugin, once Java cause error message appears…

Bottom line – if machine is up to date – well, leave it, there are plenty of easy targets around.

Except for Cool Exploit Kit. Let me show You some fun stuff there…

Tags : CoolEK forensics malware

2 comments

Security is everyone’s concern, or why Blacklisting fail.

2013.03.12

“Democracy is the worst form of government, except for all those other forms that have been tried from time to time.” (Winston Churchill)

I wrote huge philosophic part here… But then – I realized, that too much ideology already dumped into Net, no need to add.

So – see mr. Churchill quote and add “BlackListing” instead of “Democracy” << this is exactly my point.

And making long story short – in providing protection against malware – blacklisting fail.

Why? Simple.

Blacklisting – “…a blacklist or block list is a basic access control mechanism that allows through all elements (email addresses, users, URLs, etc.), except those explicitly mentioned. Those items on the list are denied access…” (WikiPedia.org)

So, basically, how it should work:

1. Someone detect that IP x.x.x.x or domain badassmalwarehomepage.com is spreading malware, got Exploit Kit installed or some other malicious activity detected

2. IP or domain list added to blacklist – now all software that work with that blacklist, protected from entering this bad site.

3. Internet Safe! (Yeah… )

And how it works now:

1. Malicious IP or domain detected. It take some time to detect new attack, discover all infectors, gather all evidence and prepare to be reported

2. IP\domain reported. There are plenty of different lists, each have it rules. Take some time to re-check and add to list – otherwise it can be used for malicious purposes.

3. Clients not up to date, lists delivered from time to time, check with list take time and traffic. And bottom line – in fastest way it take 2-3 days to get stuff done. Attacker already got profit, monetized and planning new attack.

Nothing new for many of You, and as I said – it’d terrible solution, but we dont have another now.

But wait – it even worse

Malware don’t need to have it’s own IP\domain exposed to victims, or even malware researchers, on any level. Let me show You, how.

Tags : forensics malware RedKit

Inside “4 horses club” malware >> social details :)

2013.02.01

It’s too big for twitter, so I post it as separate blog post.

Some time ago I posted info about ransomware from “4 horses club”. Grab it HERE.

Here is login page of this Aff program for partners (click for bigger pic)

Tags : forensics malware self-study

“Four Horses Club” – social networking locker malware -[Updated]

2012.12.27

This post is about “private” installs\monetize service named “Club Four Horses”:

Actually, this is malicious service “affiliate program” to convert installs on RU zone and Russian-speaking users around the world. Since it localized to RU zone, You may say, that it’s less interesting, but wait Implementation is for RU, but idea …

Tags : forensics malware virus removal

DNS switch as anti-forensics feature in Malware

2012.12.20

Recent malware sample, that was grabbed by me (and few other’s, I am certain), perform very interesting thing:

Have a look at code:

It literally change main DNS server on victim machine, and then – perform look-up for it C&C, based on pseudo-random domain.

Interesting, I say especially, if You do DNS cache review/passive DNS monitor for living

As I see, in this particular case, even if malware not succeeded to switch DNS server, it continue to run.

So, our purpose is to prevent it from doing this.

How? … Group Policy!

Create new, go to User Configuration\Administrative Templates\Network\Network Connections and on “Prohibit access to properties of a LAN connection” policy do Enable

Actually, it prevent any user on computer, even Local Admin, from changing network configuration manually.

In addition – its Recommended to have internal DNS server for LAN and on border router block outgoing DNS traffic from IP’s that different from IP’s of Your internal DNS server.

Additional info about this piece of malware:

Size: 890 Kb

SHA: 72d25f65ba822eb314a43321546ccf698a4b30e51f37406c27846671543e621f

VT: [18/45]: https://www.virustotal.com/file/72d25f65ba822eb314a43321546ccf698a4b30e51f37406c27846671543e621f/analysis/

Must see in comments to this file – analysis of binary done by @unixfreaxjp

Similar sample analysis by Conrad Longmore at Dynamoo’s Blog here

Stay Safe

D.L.

Tags : forensics hardening malware technical

1 comment

Refresh HTTP header in EK Landing Page, or “200% success attack”

2012.12.09

Yesterday, some brief review of casual threat draw my attention by serving two different Exploit Kits landing pages thru one include.

Actually, its not new, because there was multiple attempts to increase surface of attack by bot-masters.

Among those methods:

1. Include different injections into hacked server webpages [lame, but worked ]

2. Use legit or barely-legit TDS (Sutra\SimpleTDS) to route traffic based on internal rules to different Exploit Kits page

3. Using various client-server solutions (scripts with embedded algorithm of traffic forward) with internal capability of routing traffic.

Here is another one And it based on very popular in marketing formula “2 in 1″

Look at recent response from Exploit Kit (RedKit in this case)

GET h00p://michellechaso.co.uk/hmiq.htm

Ok, You say, what interesting in this (yeah-yeah, some changes in RedKit landing page, I saw them too ) look at HTTP header!

Refresh: 20; URL=h00p://link_2_malware.domain/links/1.php

This is something new (for me, at least).

Let’s look at HTTP_Headers cheat sheet.

So, in simple words it command to browser: stay on this page 20 seconds, then move to next link.

Next link is BlackHole2 EK, that lead us to Kelihos.F variants droppers.

Technically, it not route traffic between different ExploitKits, it literally infect victim twice:

1. Redkit Drop it’s payload in first 20 seconds.

2. After 20 seconds, victim redirected to BlackHole2 EKand infected again.

Have to say, that it’s common practice, to rent “installs” of malware on infected machines, to increase “return” ratio. But method is new, so be aware and stay protected

Stay Safe!

D.L.

Tags : BlackHole forensics malware RedKit technical