Story of a signed, weak, ad-injecting driver

Malware analysis includes finding out menace actor TTPs, mapping infrastructure, analyzing novel strategies… And whereas most of those investigations construct on current analysis, typically they begin from a hunch, one thing that appears too easy. On the finish of 2023, we stumbled upon an installer named HotPage.exe that deploys a driver able to injecting code into distant processes, and two libraries able to intercepting and tampering with browsers’ community visitors. The malware can modify or change the contents of a requested web page, redirect the person to a different web page, or open a brand new web page in a brand new tab based mostly on sure situations.

The installer was detected by most safety merchandise as an adware element however what actually piqued our curiosity was the embedded driver signed by Microsoft. In response to its signature, it was developed by a Chinese language firm named 湖北盾网网络科技有限公司 (machine translation: Hubei Dunwang Community Know-how Co., Ltd), the lack of awareness about which was intriguing. The distribution methodology remains to be unclear however based on our analysis, this software program was marketed as an “Web café safety answer” aimed toward Chinese language-speaking people. It purports to enhance the online shopping expertise by blocking adverts and malicious web sites, however the actuality is kind of totally different – it leverages its browser visitors interception and filtering capabilities to show game-related adverts. It additionally sends some details about the pc to the corporate’s server, most definitely to collect set up statistics.

On prime of its apparent mischievous conduct, this kernel element unintentionally leaves the door open for different threats to run code on the highest privilege stage accessible within the Home windows working system: the SYSTEM account. As a result of improper entry restrictions to this kernel element, any processes can talk with it and leverage its code injection functionality to focus on any non-protected processes.

We reported this driver to Microsoft on March 18^th, 2024 and adopted their coordinated vulnerability disclosure course of. Microsoft Safety Response Middle (MSRC) decided that that is not a vulnerability because the offending driver was faraway from the Home windows Server Catalog on Could 1^st, 2024. ESET applied sciences detect this menace as Win64/HotPage.A and Win64/HotPage.B.

Who’s 湖北盾网网络科技有限公司 ?

Throughout its execution, the HotPage malware installs a driver, however earlier than diving into the technical particulars of its internal workings, we needed to study extra concerning the code-signing signature of this driver. What first caught our consideration was the signing certificates’s proprietor, as illustrated in Determine 1.

Because the 64-bit model of Home windows 7, kernel-mode drivers have been required to be signed to be loaded by the working system. As beforehand detailed by Mandiant Intelligence, SentinelLabs, and G DATA groups, the signing course of is constructed on belief however there have been instances the place this was abused. Evidently the Chinese language firm went by way of Microsoft’s driver code-signing necessities and managed to acquire an Prolonged Verification (EV) certificates as proven in Determine 2.

To be able to retrieve the corporate title related to this signature, the extraction of the signers’ attributes was obligatory. Determine 3 reveals the SpcSpOpusInfo attribute recognized by the thing ID 1.3.6.1.4.1.311.2.1.12.

Utilizing the LIEF binary parser, it’s doable to extract the construction member programName that identifies the corporate behind this signature, as displayed in Determine 4.

We discovered a reference to this firm within the Home windows Server Catalog, as proven in Determine 5. The corporate used varied product classes when submitting its drivers for certification. Based mostly on its title, it seems the corporate developed two community filtering packages: a netfilter element and the HotPage driver referred as adsafe or by its inside title KNewTalbeBase (Notice the [Tt]albe typo, which additionally happens elsewhere within the HotPage code).

Investigating the corporate by way of search engines like google and yahoo didn’t yield many outcomes. In response to the corporate register dingtalk, we found that the corporate was created on January 6^th, 2022 and supplied the e-mail tackle dwadsafe@mail[.]io. The enterprise scope contains: technology-related actions comparable to growth, companies, consulting, and so forth., but additionally promoting actions. As translated in Determine 6, the principal shareholder is now Wuhan Yishun Baishun Tradition Media Co., Ltd, a really small firm that appears to be specialised in promoting and advertising.

From the Mental Property tab, we realized that in April and Could 2022 the corporate utilized for the commerce title Defend Web Café Safety Protection and the web site dwadsafe[.]com was created on February 22^nd, 2022. The area now resolves to localhost (127.0.0.1) and is due to this fact inaccessible. Nevertheless, a screenshot of the web site was taken on November 10^th, 2023 by a net crawler, as seen in Determine 7.

The HTTP physique of the URL https://www.dwadsafe[.]com/login/reg.html (SHA-1: 744FFC3D8ECE37898A0559B62CC9F814006A1218) was additionally captured by VirusTotal. The supply code comprises the outline 网吧主动防御云平台 (machine translation: Web café energetic protection cloud platform). This web page features a license settlement that particulars the aim of the software program, albeit with contradictions. Desk 1 lists some attention-grabbing bits of that info.

Desk 1. Translation of the related components of the license settlement

Authentic textual content	Translated textual content (by way of Google Translate; emphasis ours)
6、DwAdsafe作为一款主动防御系统，自身并不具有任何拦截功能，单独运行本软件不会对现有任何软件或者程序有拦截、破坏、修改等操作，也不会拦截任何病毒程序。用户只有在编写相关过滤规则后，才会开始生效；用户可以根据自己的实际需要，选择是否使用这些规则.	6. As an energetic protection system, DwAdsafe doesn’t have any interception perform. Working this software program alone won’t intercept, destroy or modify any current software program or packages, nor will it intercept any virus packages. Solely after customers write related filtering guidelines will they take impact; customers can select whether or not to make use of these guidelines based on their precise wants.
7、DwAdsafe是应用户的强烈需求而开发的：目前，有部分软件和网站的广告对用户存在较大的骚扰和误导，严重影响用户的上网体验。应广大用户提出要求，本公司开发并提供网吧环境下的安全监视、监控、过滤等功能的软件——DwAdsafe。DwAdsafe中所有的过滤规则均由网友提供并共享，通过DwAdsafe发布。用户可以根据自己的实际需要，选择是否使用这些功能。	7. DwAdsafe was developed in response to the sturdy wants of customers: At current, the ads of some software program and web sites are fairly harassing and deceptive to customers, significantly affecting customers’ on-line expertise. In response to requests from customers, our firm develops and offers software program for safety monitoring, monitoring, filtering and different capabilities in Web café environments – DwAdsafe. All filtering guidelines in DwAdsafe are supplied and shared by netizens and printed by way of DwAdsafe. Customers can select whether or not to make use of these capabilities based on their precise wants.
8、DwAdsafe是主动防御型软件，故包括但不限于拦截、监视、删除、结束等功能。使用DwAdsafe会对计算机信息系统的部分或全部有对应的控制及处理权限,	8. DwAdsafe is an energetic protection software program, so it contains however just isn’t restricted to interception, monitoring, deletion, termination and different capabilities. Utilizing DwAdsafe could have corresponding management and processing authority over half or the entire pc info system.

In response to the license settlement, the software program is certainly marketed as a safety answer for web cafés to dam adverts. Nevertheless, regardless of the corporate’s claims that DwAdsafe doesn’t have any interception functionality, our investigation revealed that the software program does have a somewhat intrusive one and comes with pre-written, unmodifiable guidelines.

Other than these bits of data, the corporate behind this malicious element stays a thriller.

HotPage evaluation

On this part we describe how the totally different parts are put in and work together with one another to realize their objective: injecting adverts into the browser. Up to now, we haven’t discovered how the malware was distributed however we consider, with low confidence, that it might need been bundled with one other software program package deal or marketed as a safety product as a result of stage of privileges wanted to put in the driving force. A couple of references promoting the product have been present in some boards in 2022; an instance is seen in Determine 8.

The installer drops the driving force on disk and begins a service to execute it. It decrypts its configuration file, which comprises an inventory of goal Chromium-based browsers and libraries. If such executables are discovered working or being loaded, the driving force tries to inject one of many listed libraries into the browser course of. After hooking network-based Home windows API capabilities, the injected library checks the URL being accessed and below sure situations, it shows one other web page to the person by way of numerous means.

The installer

The installer we analyzed (SHA-1: 941F0D2D4589FB8ADF224C8969F74633267B2561) is a UPX-compressed file that was uploaded to VirusTotal on 2023-08-26. Determine 9 offers a high-level overview of the driving force set up.

The installer comprises the encrypted variations (single-byte XOR operation with the important thing 0xE3) of the driving force element, the libraries that might be injected into net browser processes, and three JSON-formatted configuration recordsdata:

• chromedll comprises the names of the focused browser libraries to hook and the focused capabilities’ sample for hooking them,
• hotPage (unused) comprises the listing of focused browsers, allowlists of command line parameters and web sites, and the homepage URL that may very well be used, and
• newtalbe comprises filtering guidelines, an API endpoint to ship primary details about the compromised pc, and one other one to handle configuration updates.

The malware begins by executing the CPUID instruction (see Hypervisor Discovery), to examine whether or not it’s working inside a virtualized setting. Then it checks if the driving force’s machine filename .KNewTableBaseIo exists and if not, it decrypts the driving force and shops it in C:WindowsShieldNetWorkBusiness. Its title is a randomly generated 7-character string adopted by the .sys extension. A service is created with the file path of the saved driver, and the random string is used because the service title. Because the begin kind is ready to SERVICE_DEMAND_START, the service must be explicitly began with a purpose to load the driving force. Oddly, this adware doesn’t implement any persistence mechanisms, or at the least not on this model.

The installer proceeds to speak with and configure the driving force by way of its machine filename utilizing I/O management codes within the following order:

1. 0x9C4013FC – ship the 32-bit hooking library that might be injected into goal net browser processes.
2. 0x9C400FFC – ship the 64-bit hooking library that might be injected into goal net browser processes.
3. 0x9C40173C – ship the chromedll configuration.

The installer retrieves the registry key related to the created service and checks to see if the values IP and port are current. These values are by no means set by this code so they’re presumably created by one other element. With out going into the small print of the community protocol, the distant server ought to serve an replace of the newtalbe configuration. The communication is encrypted with RC4, utilizing a key derived from the string ID:f~WdH+Okay?KD)r*sD4mk utilizing the Home windows BCryptGenerateSymmetricKey perform. Determine 10 reveals the content material of the configuration file.

Desk 2 describes the vital values used from this file, listed within the order that they seem within the configuration file (Determine 10).

Desk 2. newtalbe configuration description

Worth	Description
cnz	URI sample matching URLs used to gather statistics when visiting the URL specified by the url worth.
url and dns	If one of many URLs listed in blist is being accessed, a brand new tab pointing to the url worth might be opened. The dns worth is IP tackle of the area.
hostapikey, hostapi, hostlist	The URL worth of hostapi is used to replace the hostlist, a dictionary comprised of game-related domains together with their corresponding IP addresses. The hostapikey is the decryption key.
apiurl	Record of endpoints to ship details about the compromised pc to.
Wlist, blist, jclist, hblist	Lists of patterns (URI, domains, file extensions, HTML code, and HTTP response headers) to match to use redirection guidelines (see the Hooking NtDeviceIoControlFile and inspecting incoming and outgoing knowledge part).

Utilizing the hostapi URL worth of this file, an HTTP GET request is revamped TLS with a generic Person-Agent string. The acquired knowledge is decrypted utilizing RC4 with the hostapikey worth; it comprises a dictionary of gaming-related hostnames with their corresponding resolved tackle.

As soon as these updates are carried out, the installer sends the up to date newtalbe configuration to the driving force by issuing an I/O request with the management code 0x9C400BFC.

Lastly, the malware iterates over the listing of endpoints supplied by the JSON aspect apiurl and for every considered one of them it creates a JSON-formatted string containing details about the compromised pc, encrypts it with RC4 utilizing the important thing Abc123!@#&XM derived by way of the Home windows API BcryptGenerateSymmetricKey, and sends the collected info to the distant server by way of an HTTP POST request. The collected info contains the pc title, the community interface MAC tackle, the model of the working system, and the size of the display.

Injector driver

The driving force’s major objective is to inject libraries into browser functions and alter their execution circulate to alter the URL being accessed or open a web page in a brand new tab. Two threads are created to deal with requests for opening a brand new tab and injecting libraries utilizing the publicly accessible Blackbone undertaking. Moreover, course of creation and picture loading notification routines are set to watch newly created processes and executable photographs being loaded. The simplified logic of the driving force is illustrated in Determine 11.

For an unknown purpose, the driving force begins by deleting its picture from the disk. Afterwards it creates a tool object named .KNewTableBaseIo and units its IRP_MJ_DEVICE_CONTROL routine to deal with the varied I/O requests listed in Desk 3. The management codes (IOCTL) used for configuration or setting the injected libraries can solely be referred to as as soon as; due to this fact the settings can’t be up to date. These particular management codes are protected by checking that the caller’s file path matches the common expression *ShieldNetWorkEnterpriseDwBusiness_*.

Desk 3. Record of obtainable IOCTLs and their description

IOCTL	Motion
0x9C400BFC	Parses the newtalbe configuration handed as an argument.
0x9C400FFC	Units the 64-bit library to be injected.
0x9C4013FC	Units the 32-bit library to be injected.
0x9C40173C	Parses the chromedll configuration handed as an argument.
0x9C401EC4	Receives an inventory of browser tabs (processes) to kill.
0x9C4027A8	Returns the hotPage configuration.
0x9C4027AC	Returns the dimensions of the hotPage configuration.
0x9C4027E8	Returns the newtalbe configuration.
0x9C4027EC	Returns the dimensions of the newtalbe configuration.
0x9C4027FC	Parses the hotPage configuration handed as an argument.

When dealing with the management codes 0x9C400BFC and 0x9C40173C, the driving force iterates over the loaded modules of all of the working processes. If one of many focused modules listed within the chromedll configuration is discovered, a request to inject a library into that course of is queued.

Lastly, the driving force ends its initialization by creating two threads and setting the notification routines talked about above.

You will need to observe that the hotPage configuration is rarely set. Any mentions of this file are solely made to explain how it will be used based on the driving force’s management circulate. Basically the hotPage configuration is used to redirect the person to a selected web page (or homepage) full of adverts when a focused browser is launched.

The model of the software program we analyzed relied solely on the chromedll and newtalbe configurations to realize its advert injection.

Library injection thread

This thread checks the queued injection requests, and for every of them, it attaches itself to the focused course of by way of KeStackAttachProcess, allocates chunks of reminiscence, and copies its shellcode. Utilizing the Blackbone library perform ZwCreateThreadEx, the driving force calls the shellcode, which implements its personal PE loader and calls the entry level of the injected library.

New tab thread

The second thread makes use of the identical logic; nonetheless, the injected shellcode is totally different. It calls the Home windows API perform CreateProcessW with the command line parameter being the method title of the focused course of concatenated with the URL that needs to be opened. The latter is fabricated from the URL adopted by the sum of the idindex and the userid variables from the hotPage configuration. As an example, the configuration proven in Determine 12 would create the string https://www.hao774[.]com/?90386-00001. Since Chromium-based browsers create a brand new course of for every new tab, making a course of from the browser course of will successfully create a brand new tab.

Determine 12 reveals the content material of the hotPage configuration file.

This configuration file comprises the listing of focused net browsers and command line parameters that decide whether or not the method needs to be injected. The domains are both associated to gaming adverts or web café upkeep.

Course of creation notification routine

Basically, this routine makes positive the homepage of the brand new net browser occasion is redirected to a selected URL current within the hotPage configuration. This part describes how the driving force implements this characteristic even when it’s not used, since this model of the installer by no means sends this configuration to the driving force.

Relying on the next situations, the online browser course of might be marked as eligible for opening the URL within the hotPage configuration:

• that is the primary occasion of the browser and never a brand new tab being opened,
• the method’s file path matches one of many common expressions within the browser listing within the hotPage configuration,
• the command line of the method doesn’t match any common expression within the wlist listing of the hotPage configuration, and
• if the method’s command line contains its personal file path, it should not match any common expressions within the ppwlist listing of the hotPage configuration.

As detailed within the subsequent part, when the browser course of begins loading the primary executable photographs, a request to open a brand new tab is queued. Determine 13 and Determine 14, respectively, present the distinction between the reputable net listing 2345[.]com and the ad-riddled web page exhibited to the person.

Picture loading notification routine

This routine primarily handles two varieties of situations. If the picture being loaded is within the chromedll listing, an APC routine is queued that may load one of many hooking libraries by way of its personal PE loader.

In any other case, if the method was marked eligible for opening a brand new web page, the malware achieves this both by opening it in a brand new tab or within the present one. If the method filename matches one of many common expressions within the browser1 listing of the hotPage configuration, a request to open a brand new tab is queued and might be dealt with by the suitable thread (observe that the browser1 listing aspect was not current within the configuration file we retrieved). Within the different case, the web page might be opened within the tab being created by queuing a piece merchandise (by way of IoQueueWorkItemEx) that may modify the command line of the method being created. The latter attaches itself to the method, finds the export tackle of GetCommandLineA and GetCommandlineW contained in the kernelbase.dll library, and modifies the Unicode string saved in BaseAnsiCommandLine. The command line is changed with the method’s executable file path concatenated with the URL within the hotPage configuration. Determine 15 reveals a side-by-side comparability of the code liable for discovering the command line buffer and the disassembly of the GetCommandLineA perform.

Injected library

The very first thing that the injected library does is to retrieve the hotPage and newtalbe configurations by querying the driving force. If the injected browser filename is 360Chrome, it deletes the registry key HKCUSoftware360chromeHomepage and patches the Preferences file (positioned below the browser’s default listing 360chromechromeUser DataDefaultPreferences) to make the homepage level to the URL worth of the hotPage configuration.

Utilizing the Microsoft Detours hooking library, the pattern hooks SetProcessMitigationPolicy to make it return 1 with a purpose to stop safety insurance policies from being utilized to the method, thereby permitting code injection. Then getaddrinfo is hooked to drive the browser to resolve sure hostnames to particular IP addresses to make sure the redirection is made to the proper server in case the domains don’t exist anymore.

Hooking SSL_read and SSL_write

The malware hooks the SSL_read and SSL_write capabilities to permit the manipulation of the browser’s decrypted TLS visitors; it does so by trying to find particular patterns contained in the loaded modules, since these capabilities usually are not exported. As an example, the chromewrite dictionary contained in the chromedll configuration comprises two varieties of patterns, sslcode and oldchrome, as seen in Determine 16. They’re, respectively, used for locating newer and older variations of the DoPayloadWrite perform. We examined and confirmed that the patterns match the Microsoft Edge library msedge.dll model 122.0.2365.80.

The mode worth is used to find out the model of the sample, both 32-bit or 64-bit; the code worth is the precise byte sample, and the offset is the space from the beginning of the sample to the pointer to the SSL_write perform (see Determine 17).

As soon as SSL_write and SSL_read are discovered, they’re hooked utilizing the Detours library. For the previous, the malware inspects the info after which calls the unique perform, which encrypts and sends it. As for the latter, the injected library does the alternative with a purpose to manipulate decrypted knowledge. For each capabilities, the info is inspected by the code that respectively handles the AFD_SEND and AFD_RECV management codes within the perform hooking NtDeviceIoControlFile.

Hooking NtDeviceIoControlFile and inspecting incoming and outgoing knowledge

The malicious library hooks the NtDeviceIoControlFile perform to deal with particular IOCTL codes as seen in Determine 18.

For the management code 0x12023 (AFD_SEND_DATAGRAM used when sending UDP packets), the malware cancels any DNS requests by returning STATUS_INVALID_PARAMETER if the distant port quantity is 53. This ensures that the online browser solely makes use of the hosts supplied by the newtalbe configuration.

The routine that handles the management code 0x1201F (AFD_SEND) begins by extracting the URL and the Referrer header from the request. Based mostly on the URL matching sure values within the newtalbe and hotPage configurations, the malware performs assorted actions, as described in Desk 4. In some instances, the request is distributed however the response is modified within the routine dealing with the AFD_RECV management code by totally different redirection strategies defined afterwards.

Desk 4. Record of actions carried out below sure situations when sending HTTP requests

Configuration	Matching worth	Motion
newtalbe	cnz	Sends information concerning the compromised pc to the apiurl (much like the tip of the installer).
hotPage	whomepage	Will increase inside homepage hit counter.
hotPage	wjclist	Sends the info with none modifications.
newtalbe	url or wlist	Sends the info with none modifications.
newtalbe	blist	Sends the info however modifies the response utilizing redirection methodology 0. The response is opened in a brand new browser tab.
newtalbe	jclist	Sends the info however modifies the response utilizing redirection methodology 1.
newtalbe	bcnzlist	Sends the info however modifies the response utilizing redirection methodology 2.
hotPage	jclist	Sends the info however modifies the response utilizing redirection methodology 3.

For management code 0x12017 (AFD_RECV), the malware first retrieves the info acquired by the consumer and checks if the response was marked eligible for redirection. There are 4 varieties of redirections as described in Desk 5. The xxx string within the modified response is modified for the URL within the newtalbe configuration.

Desk 5. Redirection strategies

Redirection methodology	Modified response	Description
0	HTTP/1.1 302 Moved Briefly Server: nginx Content material-Sort: textual content/html Connection: shut Location: xxx	Redirect the person to a different web page utilizing the HTTP code 302; an inside redirection counter is incremented.
1	<html><head><meta charset=”utf-8″><meta content material=”at all times” title=”referrer”></head><physique scroll=no type=”margin:0;padding:0″><iframe src=”https://www.welivesecurity.com/en/eset-research/hotpage-story-signed-vulnerable-ad-injecting-driver/xxx” width=100% top=100% frameborder=0></iframe></physique></html>	Exchange the content material of the present web page with an iframe pointing to a brand new URL.
2	location.change(“https://www.welivesecurity.com/en/eset-research/hotpage-story-signed-vulnerable-ad-injecting-driver/xxx”)	Redirect the present web page utilizing the change methodology of the Location interface.
3	HTTP/1.1 302 Moved Briefly Server: nginx Content material-Sort: textual content/html Connection: shut Location: xxx	Similar as redirection 0 however the redirection counter just isn’t incremented.

Determine 19 illustrates redirection methodology 0 being utilized after navigating to a URL matching one of many blist URL patterns of the newtalbe configuration (www.5zy[.]cn). One other tab is opened and factors to the url laid out in the identical configuration.

Safety points and privilege escalation

When initializing its machine object, the driving force doesn’t specify any entry management lists (ACLs) to limit who can talk with it; due to this fact, anybody can ship I/O requests to it. As talked about beforehand, some I/O management codes require the requesting course of to be in a path matching the regex:

*ShieldNetWorkEnterpriseDwBusiness_*

That is clearly not adequate to examine whether or not the speaking course of is without doubt one of the HotPage parts and may simply be bypassed by creating the required directories below a user-writable folder.

We got here up with two situations that may permit a person with the HotPage driver working on their system to run code because the NT AUTHORITYSystem account. We created a proof-of-concept (PoC) script in Python to realize each situations.

Situation #1: Privilege escalation by way of arbitrary DLL injection in arbitrary processes

On this first state of affairs, we assume that the driving force was loaded however that the chromedll configuration and the libraries to inject it weren’t set. In that case, it’s doable to create and set our personal library to inject. We created a small library that may merely log the PID of the injected course of, whether or not it’s working with administrator privileges, and the injected course of’s file path.

As seen within the screenshot of the log file in Determine 20, a number of processes have been injected with our library together with processes with administrator privileges.

It needs to be famous, nonetheless, that protected processes can’t be injected utilizing this method.

Situation #2: Privilege escalation by way of altering the command line of newly created processes

Within the first state of affairs, we relied on the truth that each the injected libraries and the chromedll configuration weren’t set, however, as seen within the installer evaluation, they’re each set as quickly as the driving force is initially loaded. Nevertheless, the hotPage configuration by no means will get set. Based mostly on the management circulate evaluation, we devised a approach to leverage the driving force’s course of creation and picture loading notification routines’ logic to execute the identical executable once more however with a special command line.

Below sure situations, as defined within the Course of creation notification routine and Picture loading notification routine sections, the driving force can open a brand new tab pointing to the URL current within the hotPage configuration. That is achieved both by changing the command line of the newly created browser course of or by duplicating the browser course of and altering its command line to the URL within the hotPage configuration. If we specify which course of may be duplicated and the brand new command line, we are able to obtain privilege escalation by focusing on a course of with SYSTEM privileges, for example.

Conclusion

The evaluation of this somewhat generic-looking piece of malware has confirmed, as soon as once more, that adware builders are nonetheless prepared to go the additional mile to realize their objectives. Not solely that, these have developed a kernel element with a big set of strategies to govern processes, however in addition they went by way of the necessities imposed by Microsoft to acquire a code-signing certificates for his or her driver element.

The HotPage driver reminds us that abusing Prolonged Verification certificates remains to be a factor. As a number of safety fashions are sooner or later based mostly on belief; menace actors are inclined to play alongside the road between reputable and shady. Whether or not such software program is marketed as a safety answer or just bundled with different software program, the capabilities granted because of this belief expose customers to safety dangers.

As annoying as adware may be, the vulnerabilities launched by this malware depart the system open to much more harmful threats. An attacker with a non-privileged account might leverage the weak driver to acquire SYSTEM privileges or inject libraries into distant processes to trigger additional injury, all whereas utilizing a reputable and signed driver.

ESET applied sciences detect this menace – which Microsoft faraway from the Home windows Server Catalog on Could 1^st, 2024 – as Win64/HotPage.A and Win64/HotPage.B.

For any inquiries about our analysis printed on WeLiveSecurity, please contact us at [email protected]

ESET Analysis affords personal APT intelligence reviews and knowledge feeds. For any inquiries about this service, go to the ESET Risk Intelligence web page.

IoCs

A complete listing of IoCs and samples may be present in our GitHub repository.

Information

SHA-1	Filename	Detection	Description
0D1D298A3EBCA4ECE0BA 52828DD3B7676D884E7F	N/A	Win64/HotPage.B	HotPage driver.
DDD82422D418FC8E8748 BCC7BD2E2BC468124A6B	N/A	Win32/HotPage.B	32-bit HotPage hooking library.
D5D646B052E8B2572399 1CB4CAB51CB2F9D55906	N/A	Win64/HotPage.A	64-bit HotPage hooking library.
941F0D2D4589FB8ADF22 4C8969F74633267B2561	Hotpage.exe	Win32/HotPage.A	HotPage installer.

Community

IP	Area	Internet hosting supplier	First seen	Particulars
61.147.93[.]49	nnijs-f-9-9-1.nycpqx[.]prime	CHINATELECOM JiangSu YangZhou IDC.	2023-10-06	Server used to acquire an inventory of game-related domains with their corresponding IP addresses.
140.210.24[.]33	tmrr-s-f-9-9-1.vosdzxhbv[.]prime	CHINATELECOM JiangSu YangZhou IDC.	2023-10-06	Compromised customers are redirected to this net server that hosts ad-riddled pages.
202.189.5[.]222	N/A	Shandong eshinton Community Know-how Co., Ltd.	2023-10-06	Former DwAdsafe area used to gather details about installations.

MITRE ATT&CK strategies

This desk was constructed utilizing model 15 of the MITRE ATT&CK framework.

Tactic	ID	Title	Description
Useful resource Improvement	T1588.003	Receive Capabilities: Code Signing Certificates	DwAdsafe’s driver is signed with a legitimate code-signing certificates.
Execution	T1204.002	Person Execution: Malicious File	The installer element is an executable utility.
	T1569.002	System Companies: Service Execution	DwAdsafe’s driver is loaded by making a service.
Persistence	T1574.013	Hijack Execution Stream: KernelCallbackTable	DwAdsafe’s driver installs kernel callbacks to watch loaded photographs and course of creation.
Protection Evasion	T1055.004	Course of Injection: Asynchronous Process Name	DwAdsafe’s driver can use APC as an injection methodology.
	T1553.002	Subvert Belief Controls: Code Signing	DwAdsafe’s driver is signed with a legitimate code-signing certificates.
	T1140	Deobfuscate/Decode Information or Data	The embedded configuration recordsdata are encrypted.
	T1055.001	Course of Injection: Dynamic-link Library Injection	DwAdsafe can hijack net browser processes’ management circulate by injecting DLLs.
	T1027.009	Obfuscated Information or Data: Embedded Payloads	DwAdsafe’s driver and hooking libraries are embedded contained in the installer.
	T1070.004	Indicator Removing: File Deletion	DwAdsafe’s driver deletes itself from disk.
	T1027.002	Obfuscated Information or Data: Software program Packing	DwAdsafe’s installer is full of UPX.
Discovery	T1033	System Proprietor/Person Discovery	DwAdsafe’s installer and the hooking libraries acquire the sufferer’s username.
Assortment	T1185	Browser Session Hijacking	DwAdsafe’s hooking libraries can intercept and tamper with community visitors inside net browser processes.
Command and Management	T1071.001	Utility Layer Protocol: Net Protocols	The HTTP protocol is used to ship collected details about the person and pc to the C&C.
	T1573.001	Encrypted Channel: Symmetric Cryptography	The RC4 encryption algorithm is used for encrypting communication with the C&C.
Influence	T1565.002	Knowledge Manipulation: Transmitted Knowledge Manipulation	DwAdsafe’s hooking libraries can intercept and tamper with community visitors inside net browser processes.