Vulnerabilities / Threats //

Advanced Threats

2/18/2016
04:50 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
100%
0%

Here Comes Locky, A Brand New Ransomware Threat

Infected Word files being used to spread ransomware, security researchers say.

If it sometimes feels like it's raining ransomware threats these days, that’s only because it is.

Cyber crooks, obviously buoyed by the growing success of their peers with using such malware, have been releasing more versions with alarming regularity. The newest one to join the increasingly crowded ranks of ransomware tools is "Locky," a somewhat awkwardly named but just as dangerous tool as the ones already floating out there.

UK-based security researcher Kevin Beaumont, who was one of the first to report on the new strain, on Wednesday reported seeing around 4,000 new infections per hour, or roughly 100,000 per day. When initially spotted about four days ago, Locky was detectable by just three antivirus products from what Beaumont described as niche vendors. Since then security vendors have updated their signatures and most major AV products now detect the malware Beaumont said in a post last updated Wednesday.

As with other ransomware tools,the operators of Locky are using it to encrypt content on infected systems and then to extract a ransom from victims in return for decrypting the content--in this case about half a Bitcoin, or roughly $210 at today’s rates.

Security researcher Lawrence Abrams, who has also been tracking Locky, described it as targeting a large number of file extensions on infected systems. “Even more importantly [it] encrypts data on unmapped network shares,” he said in a blog post on BleepingComputer.com.

“Encrypting data on unmapped network shares is trivial to code,” he said. The fact that another recent ransomware tool, dubbed DMA Locker, had the exact capability suggests this will become the norm going forward, he said. Locky is also similar to CryptoWall in that it changes the filenames for files it encrypts, making it harder to restore the right data, he added.

Locky is being distributed via a Microsoft Word attachment with malicious macros in it. Victims typically receive an email with an attached Word document purporting to be an invoice seeking payment for some product or service. Recipients who click on the attachment are presented with a document containing scrambled content and an instruction to click on an Office macro to unscramble it. Once enabled, the macro downloads Locky, stores it in the Temp folder and executes it.

Stu Sjouwerman, CEO of security vendor KnowBe4 said one way for enterprises to mitigate the risk is to disable all except digitally signed Office macros from running. If implemented correctly, users will not even see the prompt asking them to enable a macro when they click on the Word document attachment that is being used to distribute Locky, he said in a blog post outlining the steps security admins can take to disable macros.

Threat actors have been using ransomware tools like Locky to devastating effect recently. Just this week for instance, Hollywood Presbyterian Medical Center in Los Angeles said it was the victim of a ransomware attack that ended with it having to pay a ransom of $17,000 to get attackers to unlock the hospital data they had encrypted.

The success of these attacks suggest that the ransomware problem is not going anywhere soon says, Dodi Glenn, vice president of cybersecurity at PC Pitstop in comments to Dark Reading. “The actors behind [such attacks] are financially stable enough to continue to build newer versions of the malware. It is crucial to have important data backed up and stored offline in the event you are hit with ransomware,” he says.

Traditional blacklist antivirus engines have been having a hard time catching ransomware because malware authors are constantly changing portions of the code to remain undetected, he said. “Services like VirusTotal.com allow the hacker to upload newly created malware to see what any of the 54 different antivirus vendors say about the file. They will continue to tweak the file until no vendor detects it,” he said.

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
RyanSepe
50%
50%
RyanSepe,
User Rank: Ninja
2/19/2016 | 8:56:08 AM
17,000 paid
Very surprising that the hospital decided to pay the ransom. I suppose they did not have sufficient backups in place. Moving forward they will hopefully be better equipped after this snafu.
RyanSepe
50%
50%
RyanSepe,
User Rank: Ninja
2/19/2016 | 8:53:50 AM
1990's
Interesting that Locky is using macros to encrypt data. Feels nostalgic of the 1990 macros that were prevalent. In this case easily mitigated with the disabling the execution of macros within office.
WebAuthn, FIDO2 Infuse Browsers, Platforms with Strong Authentication
John Fontana, Standards & Identity Analyst, Yubico,  9/19/2018
Turn the NIST Cybersecurity Framework into Reality: 5 Steps
Mukul Kumar & Anupam Sahai, CISO & VP of Cyber Practice and VP Product Management, Cavirin Systems,  9/20/2018
NSS Labs Files Antitrust Suit Against Symantec, CrowdStrike, ESET, AMTSO
Kelly Jackson Higgins, Executive Editor at Dark Reading,  9/19/2018
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: "I'm not sure I like this top down management approach!"
Current Issue
Flash Poll
The State of Ransomware
The State of Ransomware
Ransomware has become one of the most prevalent new cybersecurity threats faced by today's enterprises. This new report from Dark Reading includes feedback from IT and IT security professionals about their organization's ransomware experiences, defense plans, and malware challenges. Find out what they had to say!
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2018-17332
PUBLISHED: 2018-09-22
An issue was discovered in libsvg2 through 2012-10-19. The svgGetNextPathField function in svg_string.c returns its input pointer in certain circumstances, which might result in a memory leak caused by wasteful malloc calls.
CVE-2018-17333
PUBLISHED: 2018-09-22
An issue was discovered in libsvg2 through 2012-10-19. A stack-based buffer overflow in svgStringToLength in svg_types.c allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact because sscanf is misused.
CVE-2018-17334
PUBLISHED: 2018-09-22
An issue was discovered in libsvg2 through 2012-10-19. A stack-based buffer overflow in the svgGetNextPathField function in svg_string.c allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact because a strncpy copy limit is miscalculated.
CVE-2018-17336
PUBLISHED: 2018-09-22
UDisks 2.8.0 has a format string vulnerability in udisks_log in udiskslogging.c, allowing attackers to obtain sensitive information (stack contents), cause a denial of service (memory corruption), or possibly have unspecified other impact via a malformed filesystem label, as demonstrated by %d or %n...
CVE-2018-17321
PUBLISHED: 2018-09-22
An issue was discovered in SeaCMS 6.64. XSS exists in admin_datarelate.php via the time or maxHit parameter in a dorandomset action.