Saturday, July 13, 2024
EHA

Hackers Attacking Windows IIS Server to Upload Web Shells

Windows IIS Servers often host critical web applications and services that provide a gateway to sensitive data and systems due to which hackers attack Windows IIS servers.

A South Korean medical establishment’s Windows IIS server with a Picture Archiving and Communication System (PACS) has been attacked, as identified by AhnLab Security Intelligence Center (ASEC), which resulted in CoinMiner infections.

There are several suspicions of web shell uploads indicating possible PACS vulnerabilities or wrongly configured safety settings.

The attacks were two different situations just days apart, probably organized by Chinese hackers who used various tools like Cpolar and RingQ, complete with Chinese annotations.

This event is an example of the continuous targeting of exposed web servers in Korea but specifically directed towards China-speaking groups emphasizing the importance of having secure measures for such critical systems like PACS in hospitals.

Scan Your Business Email Inbox to Find Advanced Email Threats - Try AI-Powered Free Threat Scan

Hackers Attacking Windows IIS Server

Firstly, an attack was launched against a Korean medical institute’s web server via upload of Chopper and Behinder web shells, followed by system reconnaissance.

For privilege escalation, BadPotato was deployed by the threat actor, while Cpolar was used for remote access. A CoinMiner came in through a “1.cab” file that contained batch script, task scheduler XML, and downloader.

Finally, some Chinese-speaking attackers had chosen the above tools and also made annotations on the scripts. 

They included several additional web shells (ASPXspy, Caidao), privilege escalation tools (PrintNotifyPotato, IIS LPE, GodPotato), port forwarding tools (Lcx, Frpc), as well as user account creation malware.

Consequently, this all-inclusive toolkit provided continuous accessibility to the compromised server, which enabled governing it, and assisted in cryptocurrency mining.

Days later, the second attack was launched on the web server of a Korean medical institution. 

The attacker also used Certutil to download additional malware and installed more privilege escalation tools such as GodPotato, PrintNotifyPotato, and CVE-2021-1732 exploit which were among others network exploration tools deployed like fscan, remote shell, and Netcat.

EarthWorm served as a proxy tool while Ladon is a multi-functional Chinese-built tool that handles different steps in an attack process.

RingQ project on GitHub (Source - ASEC)
RingQ project on GitHub (Source – ASEC)

Besides that, evidence suggests that the threat actor may be a Chinese speaker, who used RingQ to encrypt and execute malware in memory to bypass file-based detection.

Consequently, they finely crafted an ASPX downloader as XMRig CoinMiner which had some of the most advanced evasion techniques or even focused on crypto mining.

Recommendations

Here below we have mentioned all the recommendations that the security analysts provide to prevent such attacks:-

  • Administrators should address file upload vulnerabilities.
  • Implement regular password changes.
  • Access controls to mitigate lateral movement risks.
  • Keep antivirus software updated.

IOCs

MD5

First Attack Case:-

– 67af0bc97b3ea18025a88a0b0201c18d: WebShell – woanware (1.aspx)

– f6591c1ab7f7b782c386af1b6c2c0e9b: WebShell – woanware (2.aspx)

– 986c8c6ee6f6a9d12a54cf84ad9b853a: WebShell – Chopper (2a.aspx)

– 2183043b19f4707f987d874ce44389e3: WebShell – Behinder (32.aspx)

– 77d507d30a155cf315f839db3bf507f7: WebShell – Behinder (1234a.aspx)

– 8d52407e143823a867c6c8330cdcb91a: WebShell – Behinder (1235a.aspx)

– 73cdd1be414dec81c6e42b83f0d04f20: WebShell – Behinder (12345a.aspx)

– 7e9f28cedfa8b012ab8646ac341a841c: BadPotato (bad1231.exe)

– 8cf601c06370612010f438fa8faa8aa7: Cpolar (cpolar.exe)

– e2753e9bc7e5880a365f035cdc5f6e77: Runner (1.bat)

– 205e6247f5a0dce8a55910354c816a61: ScheduleTask (1.xml)

– e13adb67739f4b485544ed99bc29f618: NSSM (service.exe)

– f3bdcd409063a42479dbb162dc7f5d21: CoinMiner downloader (svchost.exe)

– fce1b5ffcaefd1dcb130f4e11cdb488d: CoinMiner downloader (sihost.exe)

– a66338d9ba331efa4918e2d6397b17fe: CoinMiner (SecurityHealthServices.exe)

– 40dc8989d4b2e3db0a9e98ef7082b0d9: WebShell – ASPXspy (aspx.txt)

– b69eb0155df920514d4ae8d44316d05a: WebShell – ASPXspy (good.txt)

– 285b5f246f994b4650475db5143e4987: WebShell – Caidao (index.txt)

– 7e1a2828650e707d8142d526604f4061: BadPotato (bad.exe)

– 83b66aae624690e82c8e011e615bce59: BadPotato (bad520.exe)

– 5f3dd0514c98bab7172a4ccb2f7a152d: GodPotato (god3.exe)

– 1fdb1dd742674d3939f636c3fc4b761f: GodPotato (god4.exe)

– 493aaca456d7d453520caed5d62fdc00: PrintNotifyPotato (P2.exe)

– 493aaca456d7d453520caed5d62fdc00: PrintNotifyPotato (P3.exe)

– 7727070eb8c69773cafb09ce77492c27: PrintNotifyPotato (P4.exe)

– f7d53946b3ae7322cd018480a2f47de8: IIS LPE (iislpe.exe)

– 10cf4d43163ee395ddad1fe7e777e2c9: IIS LPE (iislpe1.exe)

– f222524766456936074f513cec2149a8: Cpolar (cpo.exe)

– d6f84855f212400314fb72d673aba27b: Frpc (F.exe)

– 62ba55ac729763037da1836b46cb84bc: Frpc (frpc.exe)

– 3c5905da1f3aecd2dccc05f6b76a1ca9: Frpc Config (frpc.txt)

– ce1f3b789b2aab2b2b833343f13b7c98: Lcx (99.exe)

– 371a2eb2800bb2beccc1a975f3073594: Lcx (Lcx.exe)

– 7abca4faa3609f86f89f1a32fe7bbcc6: UserAdder (UserAdd.exe)

– e8a7e8bb090da018b96aab3a66c7adeb: UserAdder Command (net.txt)

– 5d9464aba77e1830e1cf8d6b6e14aa55: UserAdder Command (useradd.bat)

Second Attack Case:-

– 71a6ba713f3f5c8e24c965487a86b5d4: WebShell – Chopper (zbngjv.aspx)

– 93abe2fcb964ec91de7d75c52d676d2d: WebShell – Chopper (bin.aspx)

– 2c3de1cefe5cd2a5315a9c9970277bd7: WebShell – Godzilla (aaa.ashx)

– 69c7d9025fa3841c4cd69db1353179cf: WebShell – Godzilla (aaa.asmx)

– 7871587d8de06edc81c163564ea4ea41: WebShell – awen (cmd.aspx)

– 10b6e46e1d4052b2ad07834604339b57: WebShell – Behinder (hi1.aspx)

– 5eeda9bfb83aacb9c3f805f5a2d41f3b: WebShell – Deleter (sklqbpbl.aspx)

– 5f3dd0514c98bab7172a4ccb2f7a152d: GodPotato (gp1.exe)

– 493aaca456d7d453520caed5d62fdc00: PrintNotifyPotato (pp.exe)

– 87562e70e958c0a0e13646f558a85d04: Privilege escalation tool – CVE-2021-1732 (aa.aspx)

– 8f7dfbec116017d632ca77be578795fd: Fscan (fscan.exe)

– 5dcf26e3fbce71902b0cd7c72c60545b: NetCat (nc.exe)

– 523613a7b9dfa398cbd5ebd2dd0f4f38: NetCat (nc64.exe)

– d76e1525c8998795867a17ed33573552: EarthWorm (ew.exe)

– 5d93629fbc80fed017e1657392a28df4: Ladon (11.exe)

– e9cb6a37c43e0393d4c656bc9f6bf556: RingQ (ringq.exe)

– 705e5d7328ae381c5063590b4f5198da: CoinMiner downloader (gzrqo.aspx)

– b81577dbe375dbc1d1349d8704737adf: CoinMiner (aspx.exe)

C&C Server URLs

– 14.19.214[.]36:6666: NetCat

– 14.19.214[.]36:3333: NetCat

– 1.119.3[.]28:7455: Frpc

Download URLs

– hxxp://sinmaxinter[.]top:7001/services.zip: CoinMiner

– hxxp://sinmaxinter[.]top:7001/C3-server25.zip: CoinMiner

– hxxp://14.19.214[.]36:6666/pp.exe: PrintNotifyPotato

– hxxp://14.19.214[.]36/aa.aspx: Privilege escalation tool – CVE-2021-1732

– hxxp://14.19.214[.]36/fscan.exe: Fscan

– hxxp://14.19.214[.]36/ew.exe: EarthWorm

– hxxp://14.19.214[.]36/11.exe: Ladon

– hxxp://14.19.214[.]36/RingQ.exe: RingQ

– hxxp://45.130.22[.]219/aspx.exe: CoinMiner

– hxxp://192.210.206[.]76/sRDI.dat: CoinMiner

Free Webinar! 3 Security Trends to Maximize MSP Growth -> Register For Free

Website

Latest articles

mSpy Data Breach: Millions of Customers’ Data Exposed

mSpy, a widely used phone spyware application, has suffered a significant data breach, exposing...

Advance Auto Parts Cyber Attack: Over 2 Million Users Data Exposed

RALEIGH, NC—Advance Stores Company, Incorporated, a prominent commercial entity in the automotive industry, has...

Hackers Using ClickFix Social Engineering Tactics to Deploy Malware

Cybersecurity researchers at McAfee Labs have uncovered a sophisticated new method of malware delivery,...

Coyote Banking Trojan Attacking Windows Users To Steal Login Details

Hackers use Banking Trojans to steal sensitive financial information. These Trojans can also intercept...

Hackers Created 700+ Fake Domains to Sell Olympic Games Tickets

As the world eagerly anticipates the Olympic Games Paris 2024, a cybersecurity threat has...

Japanese Space Agency Spotted zero-day via Microsoft 365 Services

The Japan Aerospace Exploration Agency (JAXA) has revealed details of a cybersecurity incident that...

Top 10 Active Directory Management Tools – 2024

Active Directory Management Tools are essential for IT administrators to manage and secure Active...
Tushar Subhra Dutta
Tushar Subhra Dutta
Tushar is a Cyber security content editor with a passion for creating captivating and informative content. With years of experience under his belt in Cyber Security, he is covering Cyber Security News, technology and other news.

Free Webinar

Low Rate DDoS Attack

9 of 10 sites on the AppTrana network have faced a DDoS attack in the last 30 days.
Some DDoS attacks could readily be blocked by rate-limiting, IP reputation checks and other basic mitigation methods.
More than 50% of the DDoS attacks are employing botnets to send slow DDoS attacks where millions of IPs are being employed to send one or two requests per minute..
Key takeaways include:

  • The mechanics of a low-DDoS attack
  • Fundamentals of behavioural AI and rate-limiting
  • Surgical mitigation actions to minimize false positives
  • Role of managed services in DDoS monitoring

Related Articles