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Microsoft is warning of a new phishing campaign undertaken by an initial access broker that involves using Teams messages as lures to infiltrate corporate networks. The tech giant's Threat Intelligence team is tracking the cluster under the name Storm-0324, which is also known by the monikers TA543 and Sagrid. "Beginning in July 2023, Storm-0324 was observed distributing payloads using an THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comCyber Attack / Malware37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

Global threat statistics

In the first half of 2023, the percentage of ICS computers on which malicious objects were blocked decreased from H2 2022 by just 0.3 pp to 34%.

Percentage of ICS computers on which malicious objects were blocked, by half year

That said, he percentage of attacked ICS computers dropped in Q1 2023, but then rose again in Q2 2023, reaching highest quarterly figure since 2022 – 26.8%.

Percentage of ICS computers on which malicious objects were blocked, by quarter

Geography

The percentage of ICS computers on which malicious objects were blocked varied across countries from 53.3% in Ethiopia to 7.4% in Luxembourg.

The percentage of computers on which malicious activity was prevented varied across regions from 40.3% in Africa to 14.7% in Northern Europe.

Percentage of ICS computers on which malicious objects were blocked, by regions

Australia and New Zealand, the United States and Canada, Western Europe, and Northern Europe historically have had the lowest percentages of ICS computers on which malicious objects are blocked.

In H1 2023, however, those were the very regions where the percentages of attacked ICS computers increased by the most percentage points.

H1 2023 changes in the percentages of ICS computers on which malicious objects were blocked, by region

Africa and the Asian regions where the percentage of ICS computers on which malicious objects are blocked historically has been high, showed a downward trend.

Percentage of ICS computers on which malicious objects were blocked in Africa and regions of Asia

Individual industries

In H1 2023, the percentage of ICS computers on which malicious objects were blocked increased in engineering and ICS integration (by 2 pp), manufacture (by 1.9 pp) and energy (by 1.5 pp).

Percentage of ICS computers on which malicious objects were blocked in selected industries

Building automation is still the leader among the industries under review.

Categories of malicious objects

Only one of the categories grew in H1 2023: denylisted internet resources. The percentage of ICS computers on which threats in this category are blocked has grown for the second half-year in a row.

Percentage of ICS* computers on which the activity of malicious objects of various categories was prevented

The percentages of ICS computers on which Spyware, Malicious documents, Malicious miners in the form of Windows executables, Ransomware were blocked had been declining since mid-2022:

Percentage of ICS computers on which the activity of malicious objects of various categories was prevented

In H1 2023, the percentage of ICS computers on which these categories of threats were blocked, dropped in virtually every region.

Main threat sources

The internet, email clients and removable devices remained the key sources of threats to computers in the operational technology infrastructure of organizations.

Percentage of ICS computers on which malicious objects from various sources were blocked

The full report has been published on the Kaspersky ICS CERT website.

 

Microsoft has released software fixes to remediate 59 bugs spanning its product portfolio, including two zero-day flaws that have been actively exploited by malicious cyber actors. Of the 59 vulnerabilities, five are rated Critical, 55 are rated Important, and one is rated Moderate in severity. The update is in addition to 35 flaws patched in the Chromium-based Edge browser since last month's

Microsoft has released software fixes to remediate 59 bugs spanning its product portfolio, including two zero-day flaws that have been actively exploited by malicious cyber actors. Of the 59 vulnerabilities, five are rated Critical, 55 are rated Important, and one is rated Moderate in severity. The update is in addition to 35 flaws patched in the Chromium-based Edge browser since last month's THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comEndpoint Security / Zero Day37.09024 -95.7128919.5819625045790815 -130.869141 64.598517495420921 -60.556641

Adobe's Patch Tuesday update for September 2023 comes with a patch for a critical actively exploited security flaw in Acrobat and Reader that could permit an attacker to execute malicious code on susceptible systems. The vulnerability, tracked as CVE-2023-26369, is rated 7.8 for severity on the CVSS scoring system and impacts both Windows and macOS versions of Acrobat DC, Acrobat Reader DC,

Adobe's Patch Tuesday update for September 2023 comes with a patch for a critical actively exploited security flaw in Acrobat and Reader that could permit an attacker to execute malicious code on susceptible systems. The vulnerability, tracked as CVE-2023-26369, is rated 7.8 for severity on the CVSS scoring system and impacts both Windows and macOS versions of Acrobat DC, Acrobat Reader DC, THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comVulnerability / Zero Day37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

Mozilla on Tuesday released security updates to resolve a critical zero-day vulnerability in Firefox and Thunderbird that has been actively exploited in the wild, a day after Google released a fix for the issue in its Chrome browser. The shortcoming, assigned the identifier CVE-2023-4863, is a heap buffer overflow flaw in the WebP image format that could result in arbitrary code execution when

Mozilla on Tuesday released security updates to resolve a critical zero-day vulnerability in Firefox and Thunderbird that has been actively exploited in the wild, a day after Google released a fix for the issue in its Chrome browser. The shortcoming, assigned the identifier CVE-2023-4863, is a heap buffer overflow flaw in the WebP image format that could result in arbitrary code execution when THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comVulnerability / Browser Security37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

A new vulnerability disclosed in GitHub could have exposed thousands of repositories at risk of repojacking attacks, new findings show. The flaw "could allow an attacker to exploit a race condition within GitHub's repository creation and username renaming operations," Checkmarx security researcher Elad Rapoport said in a technical report shared with The Hacker News. "Successful exploitation of

A new vulnerability disclosed in GitHub could have exposed thousands of repositories at risk of repojacking attacks, new findings show. The flaw "could allow an attacker to exploit a race condition within GitHub's repository creation and username renaming operations," Checkmarx security researcher Elad Rapoport said in a technical report shared with The Hacker News. "Successful exploitation of THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comSoftware Security / Vulnerability37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

One of the new Linux networking features we've been looking forward to seeing in the kernel is TCP Authentication Option (TCP-AO / RFC5925) as a means of improving TCP security and authenticity. The eleventh iteration of the TCP-AO patches were posted today for the Linux kernel with it looking like work on this network addition potentially wrapping up soon.

SaaS applications are the backbone of modern businesses, constituting a staggering 70% of total software usage. Applications like Box, Google Workplace, and Microsoft 365 are integral to daily operations. This widespread adoption has transformed them into potential breeding grounds for cyber threats. Each SaaS application presents unique security challenges, and the landscape constantly evolves

SaaS applications are the backbone of modern businesses, constituting a staggering 70% of total software usage. Applications like Box, Google Workplace, and Microsoft 365 are integral to daily operations. This widespread adoption has transformed them into potential breeding grounds for cyber threats. Each SaaS application presents unique security challenges, and the landscape constantly evolves The Hacker Newshttp://www.blogger.com/profile/16801458706306167627noreply@blogger.comSaaS Security / CISO37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

A threat actor called Redfly has been linked to a compromise of a national grid located in an unnamed Asian country for as long as six months earlier this year using a known malware referred to as ShadowPad. "The attackers managed to steal credentials and compromise multiple computers on the organization's network," the Symantec Threat Hunter Team, part of Broadcom, said in a report shared with

A threat actor called Redfly has been linked to a compromise of a national grid located in an unnamed Asian country for as long as six months earlier this year using a known malware referred to as ShadowPad. "The attackers managed to steal credentials and compromise multiple computers on the organization's network," the Symantec Threat Hunter Team, part of Broadcom, said in a report shared with THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comCritical Infrastructure Security37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

A sophisticated phishing campaign is using a Microsoft Word document lure to distribute a trifecta of threats, namely Agent Tesla, OriginBotnet, and RedLine Clipper, to gather a wide range of information from compromised Windows machines. "A phishing email delivers the Word document as an attachment, presenting a deliberately blurred image and a counterfeit reCAPTCHA to lure the recipient into

A sophisticated phishing campaign is using a Microsoft Word document lure to distribute a trifecta of threats, namely Agent Tesla, OriginBotnet, and RedLine Clipper, to gather a wide range of information from compromised Windows machines. "A phishing email delivers the Word document as an attachment, presenting a deliberately blurred image and a counterfeit reCAPTCHA to lure the recipient into THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comEndpoint Security / Malware37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641

UPDATE 13.09.2023. Free Download Manager team issued an official statement regarding this incident.

Over the last few years, Linux machines have become a more and more prominent target for all sorts of threat actors. According to our telemetry, 260,000 unique Linux samples appeared in the first half of 2023. As we will demonstrate in this article, campaigns targeting Linux can operate for years without being noticed by the cybersecurity community.

We discovered one such long-lasting attack when we decided to investigate a set of suspicious domains, among them:

• 2c9bf1811ff428ef9ec999cc7544b43950947b0f.u.fdmpkg[.]org
• c6d76b1748b67fbc21ab493281dd1c7a558e3047.u.fdmpkg[.]org
• 0727bedf5c1f85f58337798a63812aa986448473.u.fdmpkg[.]org
• c3a05f0dac05669765800471abc1fdaba15e3360.u.fdmpkg[.]org

To a security researcher’s eye, these domains look alarming, as they can be a sight of malware using domain-generation algorithms for C2 communications. We thus decided to take a close look at the fdmpkg[.]org domain.

A malicious Debian repository

We identified that the domain in question has a deb.fdmpkg[.]org subdomain. Going there in the browser shows the following web page:

As suggested by the page, this subdomain claims to host a Debian repository of a piece of software called ‘Free Download Manager’. We further discovered a Debian package of this software available for download from the https://deb.fdmpkg[.]org/freedownloadmanager.deb URL. This package turned out to contain an infected postinst script that is executed upon installation. This script drops two ELF files to the paths /var/tmp/crond and /var/tmp/bs. It then establishes persistence by creating a cron task (stored in the file /etc/cron.d/collect) that launches the /var/tmp/crond file every 10 minutes.

The version of Free Download Manager installed by the infected package was released on January 24, 2020. Meanwhile, the postinst script contains comments in Russian and Ukrainian, including information about improvements made to the malware, as well as activist statements. They mention the dates 20200126 (January 26, 2020) and 20200127 (January 27, 2020).

A DNS-based backdoor

Once the malicious package is installed, the executable /var/tmp/crond gets launched on every startup through cron. This executable is a backdoor, and it does not import any functions from external libraries. To access the Linux API, it invokes syscalls with the help of the statically linked dietlibc library.

Upon startup, this backdoor makes a type A DNS request for the <hex-encoded 20-byte string>.u.fdmpkg[.]org domain. In response to this request, the backdoor receives two IP addresses that encode the address and port of a secondary C2 server. The following addresses were returned at the time of our research:

• 172.111.48[.]101
• 127.1.0[.]80

The first IP address in the list above is the address of the secondary C2 server, while the second address contains the connection port (encoded in the third and fourth octets) and the connection type (encoded in the second octet).

After parsing the response of the DNS request, the backdoor launches a reverse shell, using the secondary C2 server for communications. The communication protocol is, depending on the connection type, either SSL or TCP. In the case of SSL, the crond backdoor launches the /var/tmp/bs executable and delegates all further communications to it. Otherwise, the reverse shell is created by the crond backdoor itself.

A Bash stealer

Having found out that the crond backdoor creates a reverse shell, we decided to check how this shell is used by attackers. To do that, we installed the infected Free Download Manager package in a malware analysis sandbox. Having analyzed the traffic generated by crond, we determined that the attackers deployed a Bash stealer to the sandbox. This stealer collects data such as system information, browsing history, saved passwords, cryptocurrency wallet files, as well as credentials for cloud services (AWS, Google Cloud, Oracle Cloud Infrastructure, Azure).

After collecting information from the infected machine, the stealer downloads an uploader binary from the C2 server, saving it to /var/tmp/atd. It then uses this binary to upload stealer execution results to the attackers’ infrastructure.

We did not observe any other activity performed via the reverse shell, and thus the whole infection chain can be described with the graph below:

Mystery of the infection vector

After analyzing all components in the chain, we wanted to find out how the infected Debian package was distributed to victims. We checked the official website of Free Download Manager (freedownloadmanager[.]org). Packages available for download from this website turned out to be hosted on the files2.freedownloadmanager[.]org domain, and they were not backdoored.

We then decided to conduct an open-source check on the fdmpkg[.]org domain. This check revealed a dozen posts on websites such as StackOverflow and Reddit, where users have been discussing problems caused by the infected Free Download Manager distribution, not realizing they actually became victims of malware. These posts were made over the course of three years – from 2020 to 2022.

In one such post on Unix Stack Exchange, the author complains about the message ‘Waiting for process: crond’ that prevents the computer from shutting down:

The responses to this post, which came from users dealing with the same problem, suggest that this issue is caused by the Free Download Manager software. They advise to remove the files /etc/cron.d/collect, /var/tmp/crond and /var/tmp/bs. However, none mention that these three files are malicious.

In another post created in 2020, a Reddit user asked whether it is OK to install Free Download Manager without running the postinst script, which, unbeknownst to the user, contained malware.

Moreover, the post author pasted the contents of the script, and another Reddit user pointed out in the comments that it may be malicious. However, these users did not identify the website distributing the infected package or find out what this script does.

We additionally found a post on Reddit mentioning that the official website of this software was distributing malware in 2015. However, the malware described in this post turned out to be unrelated to the campaign that we discovered.

All these posts on social networks made us think that the malicious Debian package could have been distributed via a supply chain attack, through the freedownloadmanager[.]org website. So, we decided to look for further facts that could prove or disprove this claim.

An unexpected redirection

While checking videos on Free Download Manager that are hosted on YouTube, we identified several tutorials demonstrating how to install this software on Linux machines. We observed the following actions that happen in all these videos:

• The video makers opened the legitimate website of Free Download Manager (freedownloadmanager[.]org) in the browser;
• They afterwards clicked on the Download button for the Linux version of the software;
• They were redirected to the malicious https://deb.fdmpkg[.]org/freedownloadmanager.deb URL that hosts the infected version of Free Download Manager.

We also noted that the redirection to the malicious deb.fdmpkg[.]org domain was not occuring in all cases. In another video posted within the same timeframe, , a user clicked on the ‘Download’ button hosted on the software website and ended up downloading Free Download Manager from the legitimate website.

Thus, it is possible that the malware developers scripted the malicious redirection to appear with some degree of probability or based on digital fingerprint of the potential victim.

We further inspected the legitimate Free Download Manager website, wanting to find out if the software developers were aware their website was potentially compromised. In one of the comments made on the software’s blog in 2021, a user complains about observing access to the 5d6167ef729c91662badef0950f795bf362cbb99.u.fdmpkg[.]org domain. A reply to this comment from the user ‘blogadmin’ says that Free Download Manager is not related to this domain and advises to make use only of official versions of the software:

However, nobody bothered to discover how this user ended up installing this suspicious version of Free Download Manager. As such, the official website of this software continued distributing the malicious Debian package until at least 2022.

Origins of the backdoor

Having established how the infected Free Download Manager package was distributed, we decided to check whether the implants discovered over the course of our research have code overlaps with other malware samples. It turned out that the crond backdoor represents a modified version of a backdoor called Bew. Kaspersky security solutions for Linux have been detecting its variants since 2013.

Code of the 2013 version of Bew (left, MD5: 96d8d47a579717223786498113fbb913) and the crond backdoor (right, MD5: 6ced2df96e1ef6b35f25ea0f208e5440)

The Bew backdoor has been analyzed multiple times, and one of its first descriptions was published in 2014. Additionally, in 2017, CERN posted information about the BusyWinman campaign that involved usage of Bew. According to CERN, Bew infections were carried out through drive-by downloads.

As for the stealer, its early version was described by Yoroi in 2019. It was used after exploitation of a vulnerability in the Exim mail server.

The Bash stealer described in 2019 (left, MD5: 8C7EFB0493B6FB805B2C2F0593DE0AB1) and the stealer used in the FDM campaign in 2022 (right, MD5: AD7F99D44931489B2C38DF7A5A166C4D)

Why wasn’t the malicious package discovered earlier?

The malware observed in this campaign has been known since 2013. In addition, the implants turned out to be quite noisy, as demonstrated by multiple posts on social networks. According to our telemetry, victims of this campaign are located all over the world, including Brazil, China, Saudi Arabia and Russia. Given these facts, it may seem paradoxical that the malicious Free Download Manager package remained undetected for more than three years.

We assess that this is due to the following factors:

• As opposed to Windows, Linux malware is much more rarely observed;
• Infections with the malicious Debian package occurred with a degree of probability: some users received the infected package, while others ended up downloading the benign one;
• Social network users discussing Free Download Manager issues did not suspect that they were caused by malware.

While the campaign is currently inactive, this case of Free Download Manager demonstrates that it can be quite difficult to detect ongoing cyberattacks on Linux machines with the naked eye. Thus, it is essential that Linux machines, both desktop and server, are equipped with reliable and efficient security solutions.

We additionally contacted the developers of Free Download Manager and notified them about this campaign. At the time of publishing this article, we had not received a response from them.

Indicators of Compromise

File checksums
b77f63f14d0b2bde3f4f62f4323aad87194da11d71c117a487e18ff3f2cd468d (Malicious Debian Package)
2214c7a0256f07ce7b7aab8f61ef9cbaff10a456c8b9f2a97d8f713abd660349 (crond backdoor)
93358bfb6ee0caced889e94cd82f6f417965087203ca9a5fce8dc7f6e1b8a3ea (bs backdoor)
d73be6e13732d365412d71791e5eb1096c7bb13d6f7fd533d8c04392ca0b69b5 (atd uploader)

File paths
/etc/cron.d/collect
/var/tmp/crond
/var/tmp/bs
/var/tmp/atd

Network indicators
fdmpkg[.]org
172.111.48[.]101

A new information stealer malware called MetaStealer has set its sights on Apple macOS, making the latest in a growing list of stealer families focused on the operating system after MacStealer, Pureland, Atomic Stealer, and Realst. "Threat actors are proactively targeting macOS businesses by posing as fake clients in order to socially engineer victims into launching malicious payloads,"

A new information stealer malware called MetaStealer has set its sights on Apple macOS, making the latest in a growing list of stealer families focused on the operating system after MacStealer, Pureland, Atomic Stealer, and Realst. "Threat actors are proactively targeting macOS businesses by posing as fake clients in order to socially engineer victims into launching malicious payloads," THNhttp://www.blogger.com/profile/09767675513435997467noreply@blogger.comEndpoint Security / Data Security37.09024 -95.7128918.780006163821156 -130.869141 65.400473836178847 -60.556641