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After taking a look at recent Korplug (PlugX) detections, we identified two larger scale campaigns employing this well-known Remote Access Trojan. This blog gives an overview of the first one, related to Afghanistan & Tajikistan. The other campaign, where the targets were a number of high-profile organizations in Russia, will be the subject of Anton Cherepanov’s presentation at the ZeroNights security conference in Moscow this week. Sometimes malware used in various attacks is unique enough to identify related incidents, which makes tracking individual botnets simpler. An example is the BlackEnergy Lite variant (also known as BlackEnergy 3) used by a group of attackers (that was then given the name Quedagh, or Sandworm) against targets in Ukraine and other countries. BlackEnergy Lite is clearly distinguishable from the numerous binaries of the more common BlackEnergy 2 also circulating in-the-wild. In other cases, attackers use more common tools for accomplishing their criminal goals. For example, the Korplug RAT (a.k.a .PlugX) is a well-known toolkit associated with Chinese APT groups and used in a large number of targeted attacks since 2012. For the past several weeks we have taken a closer look at a great number of detections of this malware in many unrelated incidents. Among these, we were able to discover several successful infections where the employed Korplug samples were connecting to the same C&C domain. DOMAIN: www.notebookhk.net Updated Date: 2013-11-12 18:03:45 Create Date: 2013-06-18 11:08:17 Registrant Name: lee stan Registrant Organization: lee stan Registrant Street: xianggangdiqu Registrant City: xianggangdiqu Registrant State: xianggang Registrant Postal Code: 796373 Registrant Country: HK Registrant Phone : +0.04375094543 Registrant Fax: +0.04375094543 Registrant Email:stanlee@gmail.com Other Korplug samples were connecting to a different domain name resolving to the same IPs as notebookhk.net: DOMAIN: www.dicemention.com Updated Date: 2013-11-12 18:05:33 Create Date: 2013-09-10 14:35:11 Registrant Name: z x Registrant Organization: z x Registrant Street: xianggangdiqu Registrant City: xianggangdiqu Registrant State: xianggang Registrant Postal Code: 123456 Registrant Country: HK Registrant Phone : +0.0126324313 Registrant Fax: +0.0126324313 Registrant Email: 123@123.com DOMAIN: www.abudlrasul.com Updated Date: 2014-10-16 14:16:27 Create Date: 2014-10-16 14:16:27 Registrant Name: gang xin Registrant Organization: gang xin Registrant Street: Argentina Argentina Registrant City: Argentina Registrant State: Argentina Registrant Postal Code: 647902 Registrant Country: AR Registrant Phone : +54.0899567089 Registrant Fax: +54.0899567089 Registrant Email: woffg89@yahoo.com Taking these C&Cs as a starting point, we were able to locate a number of victims infected through various exploit-laden spear-phishing documents and cunningly-named archives. A table with a selection of RTF documents and RAR self-extracting archives with a .SCR extension is shown below: [table=width: 500, class: grid, align: center] [tr] [td]File name[/td] [td] English translation[/td] [td]SHA1[/td] [/tr] [tr] [td]Situation Report about Afghan.doc[/td] [td][/td] [td]36119221826D0290BC23371B55A8C0E6A84718DD[/td] [/tr] [tr] [td]AGREEMENT BETWEENTHE NATO AND AFGHANISTAN ON THE STATUS OF NATO FORCES IN AFGHANISTAN.doc[/td] [td][/td] [td]A6642BC9F3425F0AB93D462002456BE231BB5646[/td] [/tr] [tr] [td]news.doc[/td] [td][/td] [td]51CDC273B5638E06906BCB700335E288807744B5[/td] [/tr] [tr] [td]???? ???????????? ?????????? ? ???????? ?????? ???????????? ??????? ?? ???? 2014 ?.scr[/td] [td]Activity plan for military units in the Volga region in July 2014[/td] [td]EA6EE9EAB546FB9F93B75DCB650AF22A95486391[/td] [/tr] [tr] [td]??????????????????????????????? ??? ?? .scr[/td] [td]Telephone directory of the Ministry of Foreign Affairs of the Kyrgyz Republic[/td] [td]D297DC7D29E42E8D37C951B0B11629051EEBE9C0[/td] [/tr] [tr] [td]? ?????? ?????????? ????????? ??????????????.scr[/td] [td]About the Center for social adaptation of servicemen[/td] [td]8E5E19EBE719EBF7F8BE4290931FFA173E658CB8[/td] [/tr] [tr] [td]???????? ??????? ??? ???.scr[/td] [td]Meeting minutes of the General Staff of the PRC[/td] [td]1F726E94B90034E7ABD148FE31EBA08774D1506F[/td] [/tr] [tr] [td]???????????? ?????? ????? ???????????.scr[/td] [td]Corrected action plan template[/td] [td]A9C627AA09B8CC50A83FF2728A3978492AEB79D8[/td] [/tr] [tr] [td]Situation Report about Afghan.scr[/td] [td][/td] [td]A9C627AA09B8CC50A83FF2728A3978492AEB79D8[/td] [/tr] [tr] [td]??????-???????????? ?????????? ? ??? ??04.10.2014.scr[/td] [td]Military and political situation in Islamic Republic of Afghanistan (IRA) on 04.10.2014[/td] [td]E32081C56F39EA14DFD1E449C28219D264D80B2F[/td] [/tr] [tr] [td]Afghan Air Force.scr[/td] [td][/td] [td]E32081C56F39EA14DFD1E449C28219D264D80B2F[/td] [/tr] [tr] [td]???? ???????????.scr[/td] [td]Action plan[/td] [td]1F726E94B90034E7ABD148FE31EBA08774D1506F[/td] [/tr] [/table] Some of the above-mentioned files also contained decoy documents: In all of the cases, three binary files were dropped (apart from decoy documents) that led to the Korplug trojan being loading into memory. exe – a legitimate executable with a Kaspersky digital signature that would load a DLL with a specific file name dll – a small DLL loader that would pass execution to the Korplug raw binary code dll.avp – raw Korplug binary The Korplug RAT is known to use this side-loading trick by abusing legitimate digitally signed executables and is a way to stay under the radar, since a trusted application with a valid signature among startup items is less likely to raise suspicion. The maliciously crafted documents are RTF files that successfully exploit the CVE-2012-0158 vulnerability in Microsoft Word. The image below shows the beginning of the CVE-2012-0158 shellcode in ASCII encoding within the document (the opcodes 60, 55, 8bec disassemble to pusha; push ebp; mov ebp, esp). Interestingly, though, the documents also contain the newer CVE-2014-1761 exploit that was extensively used in targeted attacks carried out by a number other malware families this year (including BlackEnergy, Sednit, MiniDuke, and others). However, this exploit is not implemented correctly due to a wrong file offset in the 1st stage shellcode. Below we see the disassembly of the 1st stage shellcode where it checks the presence of the tag “p!11” marking the beginning of the 2nd stage shellcode and loads it into memory. Even though the tag and 2nd stage shellcode is present in the RTF, it’s at a different offset, and thus never is loaded. Sophos’ Gabor Szappanos gives a possible explanation how these malformed samples may have come into existence. ESET LiveGrid telemetry indicates that the attacks against these targets have been going on since at least June 2014 and continue through today. We were able to pinpoint the targets to residents of the following countries: Afghanistan Tajikistan Russia Kyrgyzstan Kazakhstan From the topics of the files used to spread the malware, as well as from the affected targets, it appears that the attackers are interested in gathering intelligence related to Afghan, Tajik and Russian military and diplomatic subjects. Interestingly, most of the affected victims have another thing in common – a number of other RATs, file stealing trojans or keyloggers were detected on their systems on top of the Korplug RAT detection. One of these ‘alternative RATs’ was connecting to a domain also used by the Korplug samples. Since the functionality of these tools was partly overlapping with that of Korplug, it left us wondering whether the attackers were just experimenting with different RATs or were they supplementing some functionality that they were unable to accomplish. Additional information about two malware families that were most often found accompanying Korplug infections is given below. Alternative Malware #1: DarkStRat A curious Remote Access Trojan, as research points to a Chinese connection but the commands it listens to are in Spanish (translation in English): CERRAR (close) DESINSTALAR (uninstall) SERVIDOR (server) INFO MAININFO PING REBOOT POWEROFF PROC KILLPROC VERUNIDADES (see units) LISTARARCHIVOS (list files) EXEC DELFILE DELFOLDER RENAME MKDIR CAMBIOID (change ID) GETFILE/SENDFILE/RESUMETRANSFER SHELL SERVICIOSLISTAR (list service) INICIARSERVICIO (start service) DETENERSERVICIO (stop service) BORRARSERVICIO (erase service) INSTALARSERVICIO (install service) The malware can manage processes and services on the infected machine, transfer files to and from the C&C server, run shell commands, and so on. It is written in Delphi and connects to www.dicemention.com. Some samples contain a digital signature by “Nanning weiwu Technology co.,ltd”. Alternative Malware #2: File Stealer This malware, written in C, and contains several functions for harvesting files off the victim’s hard drive according to criteria set in the configuration file. Apart from doing a recursive sweep of all logical fixed and remote drives, it also continually monitors any attached removable media or network shares by listening to DBT_DEVICEARRIVAL events. In addition to collecting files, the malware attempts to gather saved passwords, history of visited URLs, account information and proxy information from the following applications: Microsoft Messenger Microsoft Outlook Microsoft Internet Explorer Mozilla Firefox The C&C domains used by this malware are: newvinta.com worksware.net Some samples of this file stealer detected in these campaigns also contain the signature by “Nanning weiwu Technology co.,ltd” – another indicator that the infections are related. List of SHA1 hashes: Korplug: 5DFA79EB89B3A8DDBC55252BD330D04D285F9189 095550E3F0E5D24A59ADD9390E6E17120039355E 5D760403108BDCDCE5C22403387E89EDC2694860 05BFE122F207DF7806EB5E4CE69D3AEC26D74190 548577598A670FFD7770F01B8C8EEFF853C222C7 530D26A9BEEDCCED0C36C54C1BF3CDA28D2B6E62 F6CB6DB20AA8F17769095042790AEB60EECD58B0 EF17B7EC3111949CBDBDEB5E0E15BD2C6E90358F 17CA3BBDDEF164E6493F32C952002E34C55A74F2 973EA910EA3734E45FDE304F20AB6CF067456551 47D78FBFB2EFC3AB9DDC653A0F03D560D972BF67 0B5A7E49987EF2C320864CF205B7048F7032300D E81E0F416752B336396294D24E639AE86D9C6BAA E930D3A2E6B2FFDC7052D7E18F51BD5A765BDB90 Alternative Malware #1: FDD41EB3CBB631F38AC415347E25926E3E3F09B6 457F4FFA2FE1CACFEA53F8F5FF72C3FA61939CCD 5B6D654EB16FC84A212ACF7D5A05A8E8A642CE20 7D59B19BD56E1D2C742C39A2ABA9AC34F6BC58D4 D7D130B8CC9BEA51143F28820F08068521763494 01B4B92D5839ECF3130F5C69652295FE4F2DA0C5 02C38EC1C67098E1F6854D1125D3AED6268540DE Alternative Malware #2: 3A7FB6E819EEC52111693219E604239BD25629E9 BF77D0BA7F3E60B45BD0801979B12BEA703B227B 55EF67AFA2EC2F260B046A901868C48A76BC7B72 A29F64CD7B78E51D0C9FDFBDCBC57CED43A157B2 34754E8B410C9480E1ADFB31A4AA72419056B622 17A2F18C9CCAAA714FD31BE2DE0BC62B2C310D8F 6D99ACEA8323B8797560F7284607DB08ECA616D8 1884A05409C7EF877E0E1AAAEC6BB9D59E065D7C 1FC6FB0D35DCD0517C82ADAEF1A85FFE2AFAB4EE 5860C99E5065A414C91F51B9E8B779D10F40ADC4 7950D5B57FA651CA6FA9180E39B6E8CC1E65B746 Research by: Anton Cherepanov Via Korplug military targeted attacks: Afghanistan & Tajikistan