Category Archives: Mass Malware

TDL Variant (Backdoor.Pihar) Clickfraud Traffic

Use these to help find infected hosts on your network…

Clickfraud domains

Clickfraud “search engine” domains

Possible Regexes for these include the below, but legitimate sites use them as well.


Involved IP Addresses

Often these are using a specific UA (not always):

Mozilla/5.0 (compatible; MSIE 1.0; Windows NT; 57473847)

Clickfraud Redirects

HTTP Method = GET
Content-Type = text/html
HTTP URI = \/(f|k|task)\/(6|24|25|26|27)(\/)?$


Base64-like Clickfraud Requests

HTTP Method = GET
Content-Type = text/html
HTTP URI = \/[a-z]\/[a-zA-Z0-9%]{50,}(%3d){1,2}\/$

Examples: FueXRoaW5ndG9USEVIMHN0c3RoYXRXM1JF%3d/

Kuluoz Updated Distribution Links

*Update 22/11/2013*

Thanks to a tip from @StopMalwar we can see another variant, using some random characters.


HTTP Method = GET
Content-Type = application/octet-stream
Regex HTTP URI for \/([a-z]{7}|mirror)\.php\?[a-zA-Z0-9+/]{42,43}(=)?$

See Examples on

They also seem to be moving either very fast, or one shot only.

Since my previous posting, somewhere along the way Kuluoz distribution links changed format.

Attack vector is the same as far as i know. It’s a zip file, requiring the user to actually extract the zip and run the executable.


2013-05-24 06:59:22
2013-10-17 00:57:50


HTTP Method = GET
Content-Type = application/octet-stream
Regex HTTP URI for \/[a-z]+\.php\?[a-z]+=[a-zA-Z0-9+/]{42,43}(=)?$


HTTP Method = GET
Content-Type = application/octet-stream
Regex HTTP URI for \/(app|main|info|get|place|item|voice|message|msg)\.php\?(message|label|id|cargo|inv|invite|vmid|wed)=

Thanks to @eplekompott and @ekse0x for helping to keep this updated!

See more Examples on

Turning Vendor Blog Posts Into Actionable Intelligence (re: Solarbot)

When i see blog posts like these, they make my day. Thanks ESET/Avast!

The actionable data from them (IMO) is the below:

Filename = *

HTTP Method = POST
Content-type = application/x-www-form-urlencoded
Content-length < 100
HTTP URI (not domain) = \/[a-z]+\/$

We’re able to use great sites like Virustotal, UrlQuery,, CleanMX,, and some simple googlefu to build more intelligence around the indicators that were given.

You can then turn around and use this in your environment to detect compromised machines. –

From VT

2013-08-28 04:15:56
2013-08-09 22:40:17

From UrlQuery

2013-08-09 04:29:35 [Russian Federation]

From CleanMX –

From VT

2013-08-28 12:16:00
2013-08-28 03:57:10 –,

From VT

2013-08-16 13:17:33

From UrlQuery

2013-09-17 15:21:12



Some additional activity is seen in Report #2 that may or may not be related… –

GET /upme/uploads/91e26a25c62c3cd91.png HTTP/1.1
User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; InfoPath.2)
Connection: Keep-Alive –

GET /l1I.php HTTP/1.1
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.71 Safari/537.36
Cache-Control: no-cache

UA is different than in either of the writeups, showing us that the binary probably isn’t using a static UA. –,,

From VT

2013-09-19 13:36:43
2013-08-31 14:23:37
2013-07-29 15:00:54
2013-07-20 20:08:27
2013-07-11 01:49:29 –

From VT

2013-08-04 –

From VT

2013-09-26 14:27:10
2013-08-07 03:28:59
2013-08-04 03:35:25
2013-08-03 12:29:25 –,

From VT

2013-09-26 14:14:29
2013-09-05 15:16:41
2013-09-05 14:01:06

From there you can build out more domains on the IPs and start building some IOCs for use in your network. Network Analysis is Iterative.

Detecting TDSS Variants

These have caught some TDSS infected hosts lately.

HTTP Method = GET
Regex HTTP URI for \/[a-z]\/[0-9]{4}\/[0-9]{1,4}\/[0-9]{13}_[0-9]{13,14}\/([0-9]+\/)?$


HTTP Method = GET
Regex HTTP URI for \/j\/js[1-9]$


You can also look for these, potentially many FPs.

HTTP Method = GET
Regex HTTP URI for \/(x|z|d)\/$

Known Malicious Domains:

References: (solved w/ TDSSKiller)

Clickfraud traffic from infected hosts

Check for this on your network to find infected hosts performing clickfraud.

HTTP Method = GET
HTTP Destination contains *=/?l=eyJhYyI6* (Thats a lower case “L”)
Regex HTTP URI for \/[0-9]{8,9}\/[A-Za-z0-9]{7}=\/\?l=[A-Za-z0-9]{300,}(==?)?$

You can base64 decode the long field at the end to see some add’l info about the activity.

Seeing this in hosts that have been compromised with Neutrino lately.

EXEs downloaded by STYX loader

Noticed some easy sigs for EXEs being downloaded by STYX loader.

RogueAV, ZA, and Zbot…

HTTP Method = GET
User-Agent = Mozilla/4.0
Content-type = application/octet-stream


HTTP Method = POST
User-Agent = Mozilla/4.0
Content-type = application/x-www-form-urlencoded

Probable ZBOT Post-Compromise Activity

Found these in a very noisy redkit attack…not totally sure that it’s ZBOT. Corrections welcome…

POST naurg. com/xhobdogfz.db
POST naurg. com/fjgmzzllvqoycbsustahfwbsuytqzhtidcjihpgvtu.rtf
POST naurg. com/issrxrdzlpofezkwhmuhymmorkplnc.7z
POST naurg. com/ixzygseaenf.log
POST ronavo .com/npjvncroe.log
POST ronavo .com/lwtirttzxoevcaztzylqbou.7z
POST ronavo .com/kaaaaaabnqayupqau.rar
POST ronavo .com/bzmqvwtwbrejgqibfkgmjirjcpwoclitfdshtsmftyuhvtwbdsqrkvgpnozym.php3

HTTP Method = POST
Content-Type = “application/x-www-form-urlencoded”
Regex HTTP URI for ^http:\/\/[a-zA-Z0-9-.]+\/[a-z]+\.(db|pif|log|rar|tpl|7z|rtf|tiff|php3|doc|pl|cgi)$

http://kargid. org/c.htm?uvZA8kUIv7AwOZCMqkqhwl7jDZUOEtWFwErdgRUr
http://joshuagsilverman .com/q.htm?tVgNliikvKhhITo2QcV1ooZ6QICtS8
http://homedecorreviews. com/g.htm?Eyl5gRHaELSinXQ9fvb8k3XUOfoOTq
http://heritageclothingcompany .com/w.htm?OomDwn2fWkkW598iEtR5afe
http://solomaquetas. com/l.htm?ZQjpwNPWV1o94aEFkSdd1vYt1ZjKWC4zOr
http://gorgeoregon. com/w.htm?f9QAXSZ4vUh6qvt43YOaauWiEfSqvZKlDjI
http://compstar .us/k.htm?oyQWBuciU6G3qqIu73gpbnxia7m2m8A8baezO51
http://canadabook .ca/y.htm?qELp27uE4QF76X65tsSEitdFC63ymvKqICc16

HTTP Method = GET
Content-Type = “application/octet-stream”
User-Agent = “Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)”
Regex HTTP URI for \/[a-z]\.htm\?

Regex HTTP URI for ^[a-zA-Z0-9:/.?-_]{57,64}$ > they all seem to be 57-64 char right now…

Slight change to Facebook malware

This is a slight change to this post.


http://heartbeat.scoundrelly .eu/load/dlimage4.php?9618

You can also catch this if its coming directly from facebook (main distibution method) with something like this:

HTTP Method = GET
HTTP Referer =
Content-type = application/force-download

Locker Post Compromise Traffic

Very Noisy Malware.

HTTP Request Method = GET
Content-type = application/octet-stream
HTTP URI ends with *.php OR *.html
Regex HTTP URI for “\/[a-z-_]{70,}\.(php|html)$” OR “\/([a-z]+(\-|_)){5,}(\-|_)?\.(php|html)$”


Finding Zeus/Zbot in your DNS logs

Regex your DNS logs with this to find hosts that are compromised.



You’ll likely see some DGA style domain lookups for other top level domains as well. .biz has less false positives.