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    Author Archive - Trend Micro

    12:00 am (UTC-7)   |    by

    Ransomware SeriesAnalysis by Jaaziel Carlos, Jonh Chua, and Rodwin Fuentes

    Ransomware has become one of the biggest problems for end users are as of late. In the past months alone, we have reported on several variants of both ransomware and crypto-ransomware, each with their own “unique” routines. We recently came across one malware family, detected as PE_VIRLOCK, as that not only locks the computer screen but also infects files—a first for ransomware.

    Ransomware Routine

    VIRLOCK variants may arrive bundled with other malware in infected computers. We have even seen one VIRLOCK variant in the CARBANAK/ANUNAK targeted attack campaign.

    Figure 1. VIRLOCK infection diagram

    Once inside the computer, VIRLOCK creates and modifies registry entries to avoid detection and ensure execution. It then locks the screen of the affected computer, disabling explorer.exe and preventing the use of taskmgr.exe. Meanwhile, it also checks the location of the affected system to display the appropriate image for the ransom message.

    Figure 2. Sample ransom message

    Read the rest of this entry »


    Information about the overall threat landscape can be gathered from many sources. One useful method is by looking at the overall activity of command-and-control (C&C) servers, as used in botnets, targeted attacks, and in attacks against the broader Internet user base.

    We are able to combine various threat intelligence sources, including feedback from the Trend Micro™ Smart Protection Network™, to get a glimpse of C&C server activity. (these are displayed in real time on the Global Botnet Map). Our findings below reflect the information we gathered throughout all of 2014. We are able to examine the location of C&C servers, the location of endpoints, as well as the malware families that use these servers.

    So what can we learn from these numbers, and can IT professionals help reduce this threat?

    Malware using more ways to ensure server communication

    We measured the most commonly used malware families, as measured by the number of command-and-control servers tied to these specific families. For all C&C server activity, these were the most commonly used families:

    1. CRILOCK
    2. RODECAP
    3. ZEUS
    4. FAKEAV

    For targeted attacks, these were the most commonly seen families:

    2. XTREME
    3. NJRAT
    5. START

    Some trends can be seen from these numbers:

    • Malware families that use domain generation algorithms (DGAs) like CRILOCK are well-represented in the lists, highlighting their popularity.  Despite the differences in underlying behavior (crypto-ransomware versus information stealers), DGAs are popular as they make blocking of malicious domains more difficult with relatively little added expenditure of effort on the part of attackers.
    • Compromised sites are also popular C&C servers. ZeuS/ZBOT and RODECAP are both known to use compromised sites for their C&C servers, and both families are known to use this particular tactic extensively.
    • Similarly, free web hosting providers and dynamic IP redirection services are commonly used by some malware families such as NJRAT and DarkComet.
    • Many remote access tools (RATs) that were initially used in targeted attacks have now been used in various cybercrime-related attacks as well. This highlights the increased availability of these RATs, as well as the low entry barrier to registering and setting up C&C domains.

    Taken together, these developments show how attackers are adopting more techniques to try and obfuscate the C&C servers under their control. This can make forensic analysis of these attacks much more difficult, making detection and attribution potentially problematic.

    Read the rest of this entry »

    Posted in Targeted Attacks | Comments Off on Investigating and Detecting Command and Control Servers

    9:28 pm (UTC-7)   |    by

    Analysis by Kenney Lu

    In recent years, we have seen a lot of reports about home routers being vulnerable to attacks. Our research as early as 2008 shows malware rigging routers to redirect users to different sites. Other attacks we have seen include backdoors and possible DNS rebinding attacks. In these scenarios, the intent and goal of the attacks are pretty straight-forward.

    Snooping Around Your Network

    We recently came across one malware, detected as TROJ_VICEPASS.A, which pretends to be an Adobe Flash update. Once executed, it attempts to connect to the home router to search for connected devices. It then tries to log in to the devices to get information. Should it be successful, it will send the information to a command-and-control (C&C) server and deletes itself from the computer.

    Figure 1. Infection chain

    A Closer Look at its Routines

    Users may encounter this malware when visiting suspicious or malicious sites hosting a supposed Flash update. Users are encouraged to download this update and install it in their computers.

    Figure 2. Site hosting fake Adobe Flash update

    Figure 3. Fake Flash update

    Once the malware is executed, it attempts to connect to the connected router through its admin console, using a predefined list of user names and passwords. If successful, the malware will attempt to scan the network to look for connected devices.

    Figure 4. Scanning for connected devices

    The malware scans for devices using HTTP, with a target IP range of 192.168.[0-6].0-192.168.[0-6].11, which are IP addresses which are assigned by home routers. The target range is hard-coded. A look at the internal log format reveals such:

    Find router IP address – start

    Searching in –

    [0] connect to 192.168. 0.0

    URL: ‘’, METHOD: ‘1’, DEVICE: ‘Apple’

    …. (skip)

    Find router IP address – end

    We noticed that the malware checks for Apple devices such as iPhones and iPads, even though those devices cannot have an HTTP open panel. However, it should be noted that the strings focus more on routers. We found that the malware uses the following strings in its search:

    • dlink
    • d-link
    • laserjet
    • apache
    • cisco
    • gigaset
    • asus
    • apple
    • iphone
    • ipad
    • logitech
    • samsung
    • xbox

    Figure 5. The search for Apple devices

    Once the malware finishes scanning, the results of the search are encrypted using base64 and a self-made encryption method. Base64 is only an encoding technique so the scan results still require an encryption method. The encrypted result will be sent to a C&C server via HTTP protocol.

    Figure 6. Encryption of scan results

    Figure 7. Sending results to the C&C server

    After it has sent the results, it will delete itself from the victim’s computer, removing any trace of it. It uses the following command to do so:

    • exe /C ping -n 1 -w 3000 > Nul & Del “%s”

    Gathering Intelligence

    Based on its routines, the malware might be used by cybercriminals as a “scout” for bigger campaigns. The intelligence gathering could be the first step in more severe attacks. The information could be stored and used for future cross-site request forgery (CSRF) attacks similar to the one discussed here. If they have previous log in credentials for specific IPs, the attack would be easier to perform. Of course, we cannot be truly certain but this seems to be the likeliest scenario for malware with this type of routine.

    Protecting Routers and Other Devices

    Whatever its ultimate goal, this malware shows the importance of securing devices—even those that might not seem like likely targets. Users should always change their routers’ default login credentials; strong passwords or passphrases are a must. Users can also opt for password management software to help them with all their passwords.

    Aside from good password habits, users should always remember other security practices. For example, they should avoid clicking links on emails as much as they can. If they need to go to a site, typing the address or using a bookmark is preferred. If their software requires updates, users can directly visit the official site for downloads. They can also opt for their applications to automatically install updates once they are available. Lastly, users should always protect their devices with security solutions. For example, they can use Trend Micro security for their computers and Trend Micro Mobile for Android and iOs for their smartphones.

    User names and passwords

    This malware uses the following list of possible user names:

    • admin
    • Admin
    • administrator
    • Administrator
    • bbsd-client
    • blank
    • cmaker
    • d-link
    • D-Link
    • guest
    • hsa
    • netrangr
    • root
    • supervisor
    • user
    • webadmin
    • wlse

    It uses the following list of passwords:

    • _Cisco
    • 0000
    • 000000
    • 1000
    • 1111
    • 111111
    • 1111111
    • 11111111
    • 111111111
    • 112233
    • 1212
    • 121212
    • 123123
    • 123123Aa
    • 123321
    • 1234
    • 12345
    • 123456
    • 1234567
    • 12345678
    • 123456789
    • 1234567890
    • 1234qwer
    • 123ewq
    • 123qwe
    • 131313
    • 159753
    • 1q2w3e4r
    • 1q2w3e4r5t
    • 1q2w3e4r5t6y7u8i9o0p
    • 1qaz2wsx
    • 2000
    • 2112
    • 2222
    • 222222
    • 232323
    • 321123
    • 321321
    • 3333
    • 4444
    • 654321
    • 666666
    • 6969
    • 7777
    • 777777
    • 7777777
    • 88888888
    • 987654
    • 987654321
    • 999999999
    • abc123
    • abc123
    • abcdef
    • access
    • adm
    • admin
    • Admin
    • Administrator
    • alpine
    • Amd
    • angel
    • asdfgh
    • attack
    • baseball
    • batman
    • blender
    • career
    • changeme
    • changeme2
    • Cisco
    • cisco
    • cmaker
    • connect
    • default
    • diamond
    • D-Link
    • dragon
    • ewq123
    • ewq321
    • football
    • gfhjkm
    • god
    • hsadb
    • ilove
    • iloveyou
    • internet
    • Internet
    • jesus
    • job
    • killer
    • klaster
    • letmein
    • link
    • marina
    • master
    • monkey
    • mustang
    • newpass
    • passwd
    • password
    • password0
    • password1
    • pepper
    • pnadmin
    • private
    • public
    • qazwsx
    • qwaszx
    • qwe123
    • qwe321
    • qweasd
    • qweasdzxc
    • qweqwe
    • qwerty
    • qwerty123
    • qwertyuiop
    • ripeop
    • riverhead
    • root
    • secret
    • secur4u
    • sex
    • shadow
    • sky
    • superman
    • supervisor
    • system
    • target123
    • the
    • tinkle
    • tivonpw
    • user
    • User
    • wisedb
    • work
    • zaq123wsx
    • zaq12wsx
    • zaq1wsx
    • zxcv
    • zxcvb
    • zxcvbn
    • zxcvbnm

    Hash of related file:

    • a375365f01fc765a6cf7f20b93f13364604f2605
    Posted in Malware | Comments Off on Malware Snoops Through Your Home Network

    The earlier Flash zero-days of the year have brought a new malware threat to the forefront: the BEDEP malware family. It has been the payload of two zero-day exploits in recent weeks: CVE-2015-0311 in late January, and CVE-2015-0313 in early February.

    While these attacks made BEDEP far more widespread, it was not exactly a new malware family either. It was first spotted in September 2014, and is believed to be involved in both advertising fraud and other botnet-related activity. Its popularity as an attack platform grew significantly in early 2015, a direct result of its use in various exploit kit attacks.

    Approximately two-thirds of the victims of BEDEP from November 2014 to February 2015 were located in the United States, with Japan making up most of the remainder. Australia and Germany were also prominent BEDEP victims. We identified more than 7600 affected victims.

    Figure 1. Distribution of BEDEP victims

    How does BEDEP arrive on user systems? The zero-day attacks earlier in the year highlight one method: exploit kits delivered to users via malvertisements on legitimate sites. Both the Angler and Hanjuan exploit kits have been used to spread BEDEP.

    Another infection vector that has been less well documented is “legitimate” software. Legitimate applications today frequently come with components that pose a security risk; we recently saw this when the Superfish adware included components that could be used to attack SSL. In these cases, it went further: the BEDEP backdoor was installed onto user systems (under the file name rifa.dll.)

    Once installed on a machine, BEDEP has fairly typical backdoor routines that would allow an attacker to take control of the machine (by downloading and running various payloads).

    More details about BEDEP, as well as best practices and available Trend Micro solutions, can be found in our BEDEP Security Brief.

    Posted in Malware | Comments Off on BEDEP: Backdoors Brought Into The Light By Flash Zero-Days

    1:54 pm (UTC-7)   |    by

    Security researchers and news outlets are reporting about a newly discovered vulnerability believed to exist since the 90s. This vulnerability, dubbed as FREAK (Factoring RSA Export Keys), forces a secure connection to use weaker encryption—making it easy for cybercriminals to decrypt sensitive information.

    Vulnerable since the 1990s

    The flaw came about in the 1990s. Back then, the US government mandated that software intended for export use “export cipher suites that involved encryption keys no longer than 512 bits.” According to researchers, that kind of encryption might have sufficed in the 90s but 512-bit RSA keys can now be decrypted in about 7 hours and for only US$100 with so much computing power readily available from the cloud.

    While this restriction was lifted in the late 90s, some implementations of TLS and SSL protocols still support these export–grade encryption modes.

    FREAK, Out in the Open

    FREAK was discovered by Karthikeyan Bhargavan at INRIA in Paris and the mitLS team. They found that OpenSSL (versions prior to 1.0.1k) and Apple TLS/SSL clients are vulnerable to man-in-the-middle (MITM) attacks. Once attackers are able to intercept the HTTPS communication between vulnerable clients and servers, they force the connection to use the old export-grade encryption.

    Attackers who “listen” in on the communication will then be able to decrypt the information with relative ease.

    Apple’s SecureTransport is used by applications running on iOS and OS X. These include Safari for iPhones, iPads, and Macs. Meanwhile, OpenSSL is used by Android browsers and other application packages. From our understanding, the attack is possible only if the OpenSSL version is vulnerable to CVE-2015-0204.

    Popular Sites Affected

    According to reports, 37% of browser-trusted sites are affected by this flaw. Affected sites include Bloomberg, Business Insider, ZDNet, HypeBeast, Nielsen, and the FBI. It bears stressing that there are country-specific sites that were also affected.

    Addressing the FREAK Flaw

    OpenSSL has provided a patch for CVE-2015-0204 in January. Apple is reportedly deploying a patch for both mobile devices and computers.

    We advise Android users to refrain from using the default Android browser in their devices. They can instead use the Google Chrome app as it is not affected by the bug. Furthermore, connections to the Google search site are not affected.

    According to Deep Security Labs Director Pawan Kinger, FREAK is a serious and very real vulnerability which may require some level of sophistication to exploit. However, its sophistication won’t dissuade determined attackers. Carrying out a FREAK exploit requires attackers to be able to first create a man-in-the-middle (MITM) attack against the servers. It would also require the ability to control an SSL session between client and server and then force that session to downgrade to the lower encryption level. Then, the attacker would have to take the weakly encrypted traffic and perform a brute force attack against it that would take several hours, as opposed to days or weeks with higher encryption.

    We are currently evaluating its exact impact and attack mechanism on servers. For the time being, we advise businesses running websites and other server applications using export grade ciphers to upgrade their systems as well as upgrading to the latest OpenSSL. Administrators can also check if their site is vulnerable by using the SSL Labs’ SSL Server Test.

    Several workarounds have been suggested by, a site dedicated to disseminating information about this vulnerability:

    • Administrators should disable support for any export suites.
    • Administrators should disable support for all known insecure ciphers and enable forward secrecy.

    Trend Micro Deep Security protects users from this vulnerability through the following DPI rule:

    • 1006485 – OpenSSL RSA Downgrade Vulnerability (CVE-2015-0204)

    Note that this rule is available for client-based Vulnerability Protection.

    Update as of March 5, 2015, 5:20 PM PST

    We have added the following DPI rules to protect servers against this threat:

    • 1006561 – Identified Usage Of TLS/SSL EXPORT Cipher Suite In Response
    • 1006562 – Identified Usage Of TLS/SSL EXPORT Cipher Suite In Request

    Update as of March 5, 2015, 9:43 AM PST

    Microsoft has confirmed all version of Windows are vulnerable. Red Hat confirmed that versions 6 and 7 of Red Hat Enterprise Linux (RHEL) are vulnerable as well. Browsers that are vulnerable to the FREAK vulnerability include Internet Explorer, Opera (Mac OS X / Linux), and Safari.




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