MS13-051 Microsoft Office bulletin was release Tuesday 11th 2013 during the traditional Patch Tuesday. This bulletin fix one vulnerability, CVE-2013-1331, with a base CVSS score of 9.3 and targeting Microsoft Office 2003 and Office for Mac (2011). This vulnerability allow remote code execution and was reported by Andrew Lyons and Neel Mehta of Google Inc.
Microsoft has also release additional information’s and it appears that some “bad guys” were using this vulnerability as a zero-day in targeted attacks. The vulnerability is related on how Microsoft Office render malformed PNG files leading to a classic stack based buffer overflow.
Malicious Office documents were referencing a malicious PNG file loaded from Internet and hosted on a remote servers. Remote servers were using scripts in order to avoid multiple times exploitation from the same source. Microsoft believe that attacks were limited to Indonesia and Malaysia.
Microsoft provided some examples of URLs invoked by the malicious Office document, and some hashes of the malicious Office binary format documents.
Information Gathering on “intent.nofrillspace.com“
By doing some researches we can find a Google cached Excel document mentioning this domain name the 2011-12-29. Domain name is mentioned as a gateway for malicious activities. Actually the web site is down, but associated IP was 220.127.116.11, hosted in the Russian Federation.
“No Frill Space” is a hosting company offering free web spaces. The company web site was still up, regarding WayBack Machine, the May 28th 2013. No additional information’s are available.
Information Gathering on “mister.nofrillspace.com“
By doing some researches we can find a Google cached web page as it appeared on 27 May 2013. Since, like the previous domain, the web site is no more available. No additional information’s are available.
Information Gathering on “www.bridginglinks.com“
Like “No Frill Space“, “BRIDGING LINKS” is a hosting company offering free web spaces. The company web site was still up, regarding WayBack Machine, the May 21th 2013. “www.bridginglinks.com” was hosted on 18.104.22.168 located in Netherlands.
If we take a look on urlQuery, we can see a submission dating of April 4th 2013, mentioning an interesting URL “hXXp://www.bridginglinks.com/somebody/4698/vw.php“. As you can see the path is the same as the path mentioned by Microsoft. “vw.php” could be one of the file used to avoid multiple times exploitation.
Joe Sandbox is also referencing Report 1482, no more available, that refer a URL “hXXp://www.bridginglinks.com/somebody/4688/vw.php?i=b95146-8a76c6cb7d84148d95ab5a4921b3839c” and a name of a Word document “virus_suspected.doc“. Associated MD5 of the document is “714876fdce62371da08c139377f23d76“, was submitted March 3th 2013, with a file size of 113.0 KB.
With the MD5 we can found a VirusTotal sample. Creation date of this document was February 25th 2013. Title of the document is “VN học gì từ vụ Philippines kiện TQ” that seem to be Vietnamese and could be translated to “VN learn from China’s conditions for Philippines“.
Document title seem to be related to the events of beginning of this year between China and Philippines regarding territory conflicts.
Here under a screenshot of the sample
Update of June 16th 2013
After doing some further investigations we noticed another Word sample (f85eaad502e51eafeae0430e56899d9b) submitted to VirusTotal October 28th 2009 and that has a creation date of October 26th 2009. A re-submission of this sample clearly detect CVE-2013-1331 !
By analyzing this sample title of the document is “The corruption of Mahathir” from autor “585“. ”The corruption of Mahathir” document is a reference to Mahathir Mohamad a Malaysian politician who was the fourth Prime Minister of Malaysia, and the document is an adaptation of a Bangkok Post article to remind people how the country has been damaged by Dr M, UMNO and his cronies.
Like the previous sample, this sample is referencing ”www.bridginglinks.com” and has exactly the same patterns.
Update of June 17th 2013
Microsoft has reference some hashes of the malicious Office documents. Here under more detailled information’s on these documents. All these malicious documents are actually only detected by Avast and Symantec.
35a6bbc6dda6a1b3a1679f166be11154 Office document
Document theme is related to telecommunications and has “Telco – XX公司2013年核心网建设方案说明” as title, that could be translated to “Telco – XX company in 2013 described the core network building program“. The document was created Wednesday March 6th 2013 and last saved by “abc“. The document initiate connexions to “hXXp://zhongguoren.hostoi.com/news/space.gif“.
fde37e60cc4be73dada0fb1ad3d5f273 Office document
Document theme is related to Susilo Bambang Yudhoyono an Indonesian politician and retired Army general officer who has been President of Indonesia since 2004. Document title is “Macam-macam critis terhadap SBY dan gerakan kabinet di situs Gerakan Anti SBY II” that could be translated to “Various critis against SBY cabinet and movement at the site of the anti SBY II“. The document was created Monday October 31th 2011 and last saved by ”xmuser“. The document initiate connexions to “hXXp://mister.nofrillspace.com/users/web8_dice/4226/space.gif“.
2f1ab543b38a7ad61d5dbd72eb0524c4 Office document
Document theme is related to Chinese zodiac previsions for 2011, and document title is “Forecast for 2011“. The document was created Monday February 7th 2011 and last saved by ”xmuser“. The document initiate connexions to “hXXp://intent.nofrillspace.com/users/web11_focus/3807/space.gif“.
28e81ca00146165385c8916bf0a61046 Office document
Document theme is Malaysian Telco. The document was created by “PDRM” and last saved by “abc“, also creation date of the document is Sunday October 14th 2012. The document initiate connexions to “hXXp://www.police28122011.0fees.net/pages/013/space.gif“.
7eb17991ed13960d57ed75c01f6f7fd5 Office document
Document theme is Indoleaks, an Indonesian equivalent of Wikileak, and document title is “Indoleaks, ‘Wikileaksnya’ Indonesia“. The document was created by “3565“, last saved by “xmuser” and created Sunday January 23th 2011. The document initiate connexions to “hXXp://mister.nofrillspace.com/users/web8_dice/3791/space.gif“.
70511e6e75aa38a4d92cd134caba16ef Office document
Document theme is surveillance devices with document title “Top 11 Aerial Surveillance Devices“. The document was last saved by “xmuser” and created Tuesday January 3th 2012. The document initiate connexions to “hXXp://intent.nofrillspace.com/users/web11_focus/4307/space.gif”
Here under a recap table of all behaviors[table "23" not found /]
My personal opinion is that:
- I can clearly confirm that the zero-day was exploited in the wild since minimum
February 2013October 2009
- the campaign was active since a while and has surely target other victims than previously thought.
I will keep you in touch with additional information’s.
On April 30th, the watering hole campaign was published on a private mailing list and the May 1st, Invicia and AlienVault publicly reported, with technical details, that United States Department of Labor (DOL) Site Exposure Matrices (SEM) website had been compromised and was hosting malicious code. This malicious code was used in watering hole attack targeting at first employees of US Dept of Energy that work in nuclear weapons programs. This malicious code was also used to gather information’s on the visitors of the compromised website.
The exploit used in this campaign was firstly reported as CVE-2012-4792, an Internet Explorer 0day used in December 2012 in CFR.org watering hole campaign and patched by Microsoft in January 2013. Despite the patch release some forks of this exploit were still used in targeted attacks against political parties, political dissidents, online medias and human right activists.
Two days later, FireEye, Invicia and AlienVault concluded that the vulnerability targeted during this attack campaign was not CVE-2012-4792 as they originally reported but a new Internet Explorer 8 vulnerability identified as CVE-2013-1347. This turnaround had unfortunately occur to late. Casual attacker, chaotic actors, organized crime and potentially other states involved in sponsored espionage had the opportunity to study the attack and recover the evidences.
Microsoft has acknowledge the vulnerability in a Microsoft Security Advisory published on May 3rd and identified as MSA-2847140 and has provide a “Fix it” solution to mitigate Internet Explorer 8 vulnerability.
Also, Adobe has announce through APSA13-03 that a critical vulnerability (CVE-2013-3336) is actually exploited against ColdFusion. This vulnerability could permit an unauthorized user to remotely retrieve files stored on the server, through “CFIDE/administrator“, “CFIDE/adminapi” and “CFIDE/gettingstarted*” directories. Adobe ColdFusion is used by DOL and this vulnerability has surely be used in order to compromise the server.
Possible Causes of Confusion between CVE-2012-4792 and CVE-2013-1347
Confusions with CVE-2012-4792 was possible due to similarities in used code and technics:
“function getCookieVal(offset)“, widely used, is also present in original CVE-2012-4792 exploit and other forks.
“function GetCookie(name)“, widely used, is also present in original CVE-2012-4792 exploit and other forks.
“function SetCookie(name,value)“, widely used, is also present in original CVE-2012-4792 exploit and other forks.
“var ua = window.navigator.userAgent.toLowerCase()“, widely used, is also present in original CVE-2012-4792 exploit and other forks.
“function DisplayInfo()” also seen in CVE-2012-4792 & CVE-2011-0611 exploits.
“function download()” & “function callback()” also seen in CVE-2012-4792 exploit.
Usage of Ajax XMLHttpRequest
Usage of HTML+TIME technic
HTML+TIME, which is based on the Synchronized Multimedia Integration Language (SMIL), was also used in certain CVE-2012-4792. This technic was explained by Exodus Intel beginning January 2013.
Parts of the code targets only Windows XP, Internet Explorer 8 and certain languages, like CVE-2012-4792.
Differences between CVE-2012-4792 and CVE-2013-1347, and Particularities
Some new particularities were present in the exploit and associated watering hole campaign:
Usage of PHP files
Usage of Base64 obfuscation
Obfuscation with base64 encoding (“base64.js” file) was used to hide parts of the exploit. CVE-2012-4792 was using “robots.txt” obfuscated with substitutions and HEX encoding.
As mentioned by sinn3r of Metasploit team, CVE-2012-4792 was a CButton object use-after-free and CVE-2013-1347 is a CGenericElement object use-after-free.
dol[.]ns01[.]us Exploit Hosting Domain Evolutions
You can observe this evolution with the urlQuery submission of 2013-04-30.
All these urlQuery submission’s were done with a non Internet Explorer 8 user agent, and as the exploit malicious code was designed to only target Windows XP and Internet Explorer 8, part of the redirection were not present as evidences.
The first inclusion “/web/xss.php” was used in order to gather information’s on the DOL website visitors and the second inclusion “/update/index.php” was used to start the exploitation of CVE-2013-1347.
Information Gathering Scripts
Also a specific information gathering technic was triggered when Internet Explorer was used. This technic is related to a non patched vulnerability in Internet Explorer 8, discovered by NSFOCUS and reported to Microsoft in 2011. The vulnerability could allow user information and even local file content leakage if a user views a specially crafted webpage using Internet Explorer.
Once all information’s gathered, the script send all data’s on a specific URL “hxxp://dol[.]ns01[.]us:8081/web/js.php” and also call “hxxp://dol[.]ns01[.]us:8081/web/css.js” when the information’s are collected.
An interesting information regarding “/web/css.js“, is that the “Last Modified” date reported by “dol[.]ns01[.]us” server is Thu, 14 Mar 2013 20:06:36 GMT. This is reporting that the information gathering infrastructure was in place since mid-March minimum.
Interesting facts regarding these information gathering scripts are:
- Scripts “xss.php“, “js.php” & “css.js” have move from IP 96[.]44[.]136[.]115 on port 80/TCP to domain dol[.]ns01[.]us port 8081/TCP. Move from port 80/TCP to 8081/TCP doesn’t seem to be logic, most of time outgoing connexion’s authorized on Firewalls, for corporate Web surfing, are 80/TCP and 443/TCP.
- Different types of information gathering scripts were in place, and all users who have visit DOL website were affected by this information gathering campaign.
- Usage of a specific information leakage vulnerability present in Internet Explorer 8 and not fixed by Microsoft.
- BitDefender 2012 deactivation attempt is confusing. Why trying to deactivate an anti-virus, this will surely generate an alert.
Information Gathered on dol[.]ns01[.]us
As described in the previous chapter, the information gathering code send a lot of information’s to the backend. Hopefully for security researchers, the backend wasn’t very well protected and all collected information’s were accessible without any restrictions in different web folders. You can find here under some statistics related to the gathered information’s.
Complete geolocation of the targeted source IPs
By analyzing the information’s sent to the backend, we can also see that DOL (www.sem.dol.gov) wasn’t the only compromised website:
- From 2013-03-15 to 2013-04-29 : University Research Co. Cambodia website (www.urccambodia.org) was the first target .This explain the high number of distinct IP addresses from Cambodia.
- From 2013-04-08 to 2013-04-24 : Awards for Excellence in Education website (www.forexcellenceineducation.org), a program of Fraser Institute, was the second target.
- From 2013-04-08 to 2013-04-24 : ElectionGuide website (www.electionguide.org), provided by the International Foundation for Electoral Systems (IFES), was the third target.
- From 2013-04-09 to 2013-04-30 : French Institute of International Relations website (www.ifri.org), was the fourth target.
- From 2013-04-09 to 2013-04-24 : The Working for America Institute website (www.workingforamerica.org), was the fifth target.
- From 2013-04-09 to 2013-04-10 : The Project 2049 Institute website (www.project2049.net), was the sixth target.
- From 2013-04-10 to 2013-04-10 : The Union Label and Service Trades Department website (www.unionlabel.org), was the seventh target.
- From 2013-04-11 to 2013-04-30 : Thales Catalogue website (components-subsystems.thales-catalogue.com), was the eighth target.
- From 2013-04-23 to 2013-05-01 : United States Department of Labor (DOL) Site Exposure Matrices (SEM) website (www.sem.dol.gov), was the ninth target.
Here under the hits by browsers and Internet Explorer 8 hits by OS.
Others Information’s Gathered
As you have read in the previous chapter, ElectionGuide website (www.electionguide.org) was also targeted during this watering hole campaign. As you can see in the following urlQuery submission, dating from 2013-05-01, 96[.]44[.]136[.]115 is also present but don’t respond any more. Also if you observe the urlQuery submission of 2013-05-03, 96[.]44[.]136[.]115 is still present, but a new backend server has been setup in order replace the once deactivated.
If you observe the “Last Modified” date of “css.js” file, the installation date of these files is at least the 2013-05-03.
Also, by researching some patterns matching the information’s gathering script on Google you can find some previous unknown campaigns, that were using the same code.
By analyzing one of the Dark South Korea dropper, I discovered interesting behaviours associated with the PuTTY binaries installed in “%TMP%” Windows folder. These behaviours could be considered as expected, but they could be used more efficiently in the future.
The two installed binaries are “alg.exe“ and “conime.exe“ used to upload “~pr1.tmp” bash file to *NIX targets discovered in configuration files of mRemote and SecureCRT.
“alg.exe“ is “plink.exe“ a PuTTY tool acting as a command-line interface to the PuTTY back ends, and “conime.exe” is “pscp.exe” PuTTY tool acting as a SCP client, i.e. command-line secure file copy. These two binaries are legit and don’t contain any associated malwares, they are only used by a malware as support tools.
If mRemote is installed, the dropper extract all required information’s (credentials, ports, ip/domain) from “confCons.xml” configuration file, and use an encryption method vulnerability in mRemote to decrypt it the stored password. After exploitation of the vulnerability, “conime.exe” is used to drop the bash file on the targeted servers.
If the latest version of SecureCRT is installed, the dropper extract all required information’s (credentials, ports, ip/domain) present in “*.ini” configuration files. Each saved connection in SecureCRT use it ones “*.ini”. It seem that an unknown vulnerability was present in previous versions of SecureCRT in order to decrypt the stored password. But in the latest version of SecureCRT, this vulnerability don’t seem to be present. So when “conime.exe” try to connect to the targeted servers the authentication fails due to a bad password.
During my research on the potential SecureCRT vulnerability, I was intrigued by “conime.exe” by access tentatives to the registry keys of PuTTY software “HKCU\Software\SimonTatham\PuTTY\Sessions” and “HKCU\Software\SimonTatham\PuTTY\SshHostKeys“.
I decided to install PuTTY, like a majority of sysadmin’s, and create an entry corresponding to potential server also recorded in SecureCRT software.
Then I execute the dropper one more time and discovered that “conime.exe“, as expected, has access the PuTTY registry keys related to the targeted server “HKCU\Software\SimonTatham\PuTTY\Sessions\192.168.178.54“. The dropper authentication tentative was still unsuccessful, du to the wrong password.
But I also observed that “conime.exe” was also trying to access another registry key of PuTTY “HKCU\Software\SimonTatham\PuTTY\SshHostKeys\rsa2@22:192.168.178.54“.
I decided then to create a private and public SSH key, and to configure my putty session to support this SSH private key authentication. The private key wasn’t protected by a passphrase.
I execute the dropper one more time and observed a successfull authentication on the targeted server. “conime.exe” was using the private key path present in PuTTY registry key.
My final test was to remove the private key from the PuTTY configuration and use “pageant.exe“, an SSH authentication agent for PuTTY, PSCP, PSFTP, and Plink. I loaded my private key in “pageant.exe” and executed the dropper one more time. Same result as the previous one, a successfull authentication on the targeted server.
- By analyzing one of the Dark South Korea dropper, with associated vulnerabilities in mRemote and SecureCRT, we can observ that the “bad guys” have use old vulnerabilities in old softwares in order to infect *NIX servers. Why use these old vulnerabilities, if you can simply target PuTTY when it is used with private keys.
- Never generate a private key without a passphrase
- Don’t let PuTTY Pageant run with charged private keys.
As mentioned by different medias, security vendors and security researchers some South Korean banks and broadcasting organizations went dark Wednesday 20 March, victim of a cyber attack. Initial impacted broadcaster were KBS, MBC and YTN, and impacted banks were Cheju, Nonghyup and Shinhan.
But by analyzing all the events related to this cyber attack we can see that the campaign was more extended in time as mentioned and also more complex to understand. The campaign is composed by different samples, created potentially by different authors with different objectives. We can divide the reported samples in different categories:
- Wipe: Objective of these samples is to erase all data’s of affected targets.
- Drop & Wipe: Objective of these samples is to drop a wiper to erase all data’s of affected targets.
- Drop & Wipe & Deface: Objectives of these samples are to drop a wiper to erase all data’s and deface website hosted by affected targets.
- Drop & Backdoor: Objective of these samples is to install a backdoor, or trojan, on the affected targets.
- Unknown: These samples are potentially not related to the campaign.
I will try, through this blog post, to provide you the most reliable information’s as possible regarding the Dark South Korea campaign.
According to different sources, and announced by the South Korean security provider AhnLab the Thursday 21 March, “bad guys” got access to AhnLab Policy Center and HAURI ViRobot ISMS, asset management tools, through stolen credentials in order to massively spread Trojan.Jokra. But, regarding the latest news announced the 29 March, it seem that AhnLab APC product was vulnerable to a login authentication bypass and that this vulnerability was used by the bad guys in order to get access to APC and spread the malware.
On Wednesday 20 March, AhnLab stocks gains of 6.5 percent (75,100 KW to 80,000 KW) from stemming from expectations of demand for online security software following the hacking incident. But after the 21 March AhnLab announcement, stocks were down 3.6 percent (from 80,000 KW to 74,700 KW). Since 21 March, AhnLab stocks have fallen from 74,700 KW to 68,100 KW.
KCC reported that around 47 800 units were impacted by this cyber attack. You will find in the following graphical representation of known impacts. This graphical representation has been inspired by the work of @piyokango, a must read blog post !
Also translated from @piyokango work, the associated event timeline. Through this timeline you can better understand all the actors and impacts involved in this cyber attack.[table "11" not found /]
The actual investigation results point that foreign source IPs ( 3 european countries and US, but not China) were discovered as potential source of the attack, and that a potential of 14 variants of the malware were discovered and analyzed.
Security firm Xecure Lab has provide some information’s regarding Dark South Korea, malwares hash are available with some detailed analysis. Also malwares samples were available on private groups and on contagio. Based on these hashes and samples, you can find here under an analysis.
Presumed Dropper(s)[table "12" not found /]
This executable drop “AgentBase.exe” (db4bbdc36a78a8807ad9b15a562515c4), “alg.exe” (e45cd9052dd3dd502685dfd9aa2575ca), “conime.exe” (6a702342e8d9911bde134129542a045b) and “~pr1.tmp” (dc789dee20087c5e1552804492b042cd) in “%TMP%“, then execute “AgentBase.exe“. Remarks: Also known as K10 by Xecure Lab, mentioned as a wiper, but it is a dropper. This sample could be categorized as Drop & Wipe.
Also, dropped “AgentBase.exe” is known as K01 on Xecure Lab, mentioned as a wiper only. “AgentBase.exe” is a Windows wiper, but also the dropper for *NIX batch wiper aka “~pr1.tmp“. More information’s in the “9263E40D9823AECF9388B64DE34EAE54 Dropper Analysis” chapter of this blog.[table "13" not found /]
It seem that “update_body.jpg” (a03ae3a480dd17134b04dbc5e62bf57b), first seen the 2012-08-28 04:31:52, is the same as mentioned on SCUMWARE the 2012-08-30. You can find this sample on malware.lu. Symantec and McAfee have try to create a relation based on the used packer and on some common compilation paths. But like McAfee, I don’t see any relations between this dropper and the 03.20 Dark South Korea campaign. Known as K06 on Xecure Lab. This sample could be categorized as Drop & Backdoor, or Unknown.[table "14" not found /]
Here also, I don’t see any relations between this dropper and the 03.20 Dark South Korea campaign. Known as K05 on Xecure Lab and mentioned by McAfee. This sample could be categorized as Drop & Backdoor, or Unknown.[table "15" not found /]
Known as K08 on xsecure-lab.com, and like the guys of Xecure Lab. I don’t see any relations between this dropper and the 03.20 Dark South Korea campaign. F-Secure has try to link this sample to the campaign. This sample could be categorized as Unknown.[table "20" not found /]
This sample was mentioned by Symantec and AhnLab the 23 March. Particularities of this sample is that he will drop 2 files and inject 1 the files into “LSASS.exe” process as a DLL. Also this sample will be executed any years the 20 March at 2pm and wipe MBR with “HASTATI.” and “PR!NCPES” strings. Unfortunately I wasn’t able to find this sample. This sample could be categorized as Drop & Wipe.[table "21" not found /]
This sample was also mentioned the 20 March by different medias, security vendors and researchers. He was used to against LG UPlus Corp showed a page that said it had been hacked by a group calling itself the “Whois Team“.
Particularities of this sample is that he seem to be triggered only in certain conditions, and this condition seem to be related to certain time zone, as mentioned by AhnLab the 23 March. The sample drop “mp.swf“, “lf.mp3“, “24mhk04.gif“, “25z18pg.jpg” files, adds “MICRO_ESENCIAL0192301” as mutex, modify the “SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management“ following registry entries, overwrite all “.html“, “.htm“, “.aspx“, “.asp“, “.jsp“, “.do“, “.php” files with its code, terminate Windows Alerter service (Alerter) and Windows System Event Notification Service (Sens), and drop all the MBR datas. This sample could be categorized as Drop & Wipe & Deface.
Despite file “~v3.log” is present in “C:\WINDOWS\Temp\” directory, the wiper is running directly. This sample could be categorized as Wiper.[table "17" not found /]
This sample could be categorized as Wiper.[table "18" not found /]
This sample is taking care of the ”~v3.log” presence in ”C:\WINDOWS\Temp\” directory. If the file is present the wipe process is not started. This sample could be categorized as Wiper.
But you have to take in consideration that this sample is normally executed by 9263E40D9823AECF9388B64DE34EAE54 dropper, and that a complete process will be analyzed in the ”9263E40D9823AECF9388B64DE34EAE54 Dropper Analysis” chapter of this blog.[table "19" not found /]
Like the previous wiper, if ”~v3.log” is present in ”C:\WINDOWS\Temp\” directory, the wipe process is not started.
This sample seems also to be part of a another dropper actually not publicly known. This sample could be categorized as Wiper.
As you can see, all of the wipers use the “HASTATI” string in order to overwrite MBR data’s. As reported by security vendors, “Hastati” term refers to a class of infantry in the armies of the early Roman Republic. “PRINCPES” term, also used to overwrite MBR data’s, could also refer to the “Principes” who were veteran soldiers of the Roman Pre-Marian Army. Are the “bad guys” fan of Roman Army, or fan of Total War game ?
Also an interesting relation between the “HASTATI” string used to overwrite MBR data’s, is that KBS TV website was defaced the 21 March with a “Defaced by HASTATI” message and symbol representing the class of infantry in the armies of the early Roman Republic.
9263E40D9823AECF9388B64DE34EAE54 Dropper Analysis
In this chapter of this long blog post we will analyze some behaviors of 9263e40d9823aecf9388b64de34eae54 dropper.
As mentioned by different security vendors or researchers, when executed the dropper will extract 4 files into Windows “%TMP%” directory. These files are “alg.exe“, “conime.exe“, “~pr1.tmp” and “AgentBase.exe“.
“alg.exe” (e45cd9052dd3dd502685dfd9aa2575ca) is the “plink.exe“ PuTTY tool acting as a command-line interface to the PuTTY back ends. This binary has been compiled the 2013-02-15 at 08:12:58.
“conime.exe” (6a702342e8d9911bde134129542a045b) is the “pscp.exe” PuTTY tool acting as a SCP client, i.e. command-line secure file copy. This binary has been compiled the 2006-03-13 at 14:32:44.
“AgentBase.exe” (db4bbdc36a78a8807ad9b15a562515c4) is the wiper mentioned in the previous chapters of this blog post.
After installing these files, the dropper will check the presence of “~v3.log” file in “C:\WINDOWS\Temp\” directory.
If the file “~v3.log“ is not existing “AgentBase.exe” wiper will be executed, killing AhnLab Policy Agent (pasvc.exe) and Hauri ViRobot ISMS Client (clisvc.exe), then erasing all data’s.
If the file ”~v3.log” is existing, the dropper start to check the presence of configuration file “confCons.xml” of mRemote program, developed by Felix Deimel, and the presence of configuration files of SecureCRT program, developed by VanDyke Software, Inc.
For mRemote, the dropper copy all data’s, related to SSH connexions with root login, present in “confCons.xml” configuration file and exploit a vulnerability present in the password storage engine of this program. When you save connections in mRemote it outputs all of that data into an XML report “confCons.xml“. The passwords are saved in an encrypted format, however this is trivial to circumvent. So despite the passwords are saved in encrypted format it is easy to decrypt them. This vulnerability was discovered and published by Cosine Security the 2 Jun 2011. Support of mRemote has been stopped in 2012.
Once the mRemote vulnerability is exploited, the dropper start a new process to execute “conime.exe” binary, in order to drop the “~pr1.tmp” file into “/tmp/cups” on the targeted server:
“C:\Users\ERICRO~1\AppData\Local\Temp\conime.exe -batch -P 22 -l root -pw test C:\Users\ERICRO~1\AppData\Local\Temp\~pr1.tmp 192.168.178.54:/tmp/cups”
After upload of “cups” file, the dropper will execute this file through the following command.
“C:\Users\ERICRO~1\AppData\Local\Temp\conime.exe -batch -P 22 -l root -pw test 192.168.178.54 “chmod 755 /tmp/cups;/tmp/cups”
For SecureCRT, the dropper is also copying all data’s, related to SSH connexions with root login, present in “*.ini” configuration files. Each saved connection in SecureCRT as it ones “*.ini” file who will be parsed by the dropper. The passwords are also saved in an encrypted format.
With the latest version of SecureCRT (7.0.3), the dropper is unable to decrypt the password, but will try to connect to targeted servers with a wrong password. So there is surely a similar vulnerability as for mRemote in previous versions of SecureCRT, but wasn’t able to find it.