Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

4/11/2017
05:40 PM
Connect Directly
Twitter
LinkedIn
Google+
RSS
E-Mail
50%
50%

Microsoft Office Zero-Day Patched After Months of Attacks

Microsoft released a security update for a flaw in the OLE API that affects most versions of Microsoft Word.

Microsoft today patched a critcial zero-day vulnerability in Microsoft Office/WordPad that attackers had been exploiting in the wild for months.

CVE-2017-0199 is a remote code execution vulnerability in the Windows Object Linking and Embedding (OLE) application programming interface. The vulnerability already had been weaponized in attacks to distribute the Dridex banking Trojan, as a botnet payload, and in a cyber espionage campaign.

Security firm McAfee published a report on April 7 to warn users of an exploit that has been used to target users since late January. SophosLabs claims attacks actually date back to November 2016, with most occuring between March and April 2017.

There are a few reasons this bug is especially dangerous: it affects most, or all, Windows versions of Microsoft Word, and targets don't have to enable macros for exploits to be effective, explains Bryan Burns, vice president of threat research and engineering at Proofpoint.

Burns says it's a logic bug, which is harder to defend against, he says. Victims are more likely to fall for these attacks because they aren't prompted to enable macros -- something businesses teach their employees to avoid. Instead, the attacks use a dialogue box.

"They've probably been trained over the last several years not to enable macros," says Burns. "This is a different vector. Users haven't seen a dialogue box. They haven't been trained not to click on it."

The attackers attach emails containing Microsoft Word RTF (Rich Text Format) documents. Subject lines read "Scan Data" and attachments were named "Scan_123456.doc" or "Scan_123456.pdf" with "123456" replaced with random numbers, Proofpoint reports.

When launched, the exploit connects to a remote server, downloads a file containing HTML application content, and executes it as a .hta file, McAfee explains. Because .hta is executable, the attacker gains full code execution on the machine. After the malware has been installed, the exploit closes the bait Word document and displays a new one to show the victim.

The exploit uses an embedded OLE2link object in specially created documents.

"Everything is working as designed," says Burns of how the attack deceives targets. "But the way it's designed, it left a corner open so code can run when you wouldn't expect it to be running."

In the case of Dridex, attackers obtained full system control to launch the banking Trojan malware. This enabled them to grab businesses' financial credentials and intercept transactions to steal money. "In this case, it was financially motivated," says Burns of the attackers' goals. "They were trying to infect with this malware to empty out [organizations'] bank accounts."

But Burns warns that this Office flaw would allow for any type of malware to be installed. Ransomware is one example Proofpoint sees frequently distributed.

"We would expect any threat actor who is trying to attack businesses to try this technique," he cautions.

Several security firms aside from Proofpoint observed this vulnerability in the wild ahead of Microsoft's patch. Netskope's Threat Research Labs linked this zero-day to the Godzilla botnet loader. Researchers saw IPs released to the botnet loader serving payloads related to exploits for the vulnerability using malicious Word documents.

In a different scenario, FireEye spotted this flaw being used in a cyber espionage campaign targeting Russian-speaking victims since January 2017 and installing FINSPY, a tool previously associated with the "lawful intercept" company Gamma Group. FireEye in another case saw exploits installing Latentbot, a malware family used by cybercriminals for financial gain.

Now that Microsoft has issued a fix, businesses should protect themselves by patching as quickly as possible, Burns says. He also cautions organizations to be wary of these types of attacks, as email as the "dominant threat vector" hackers will use to infect businesses.

Meanwhile, today is the last day of extended support for Windows Vista. The OS will no longer receive updates or support from Microsoft. 

Related Content:

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Threaded  |  Newest First  |  Oldest First
technicalaccademy
50%
50%
technicalaccademy,
User Rank: Apprentice
4/12/2017 | 1:28:49 AM
Microsoft
Thanks for sharing the microsoft office zero-day.
Data Leak Week: Billions of Sensitive Files Exposed Online
Kelly Jackson Higgins, Executive Editor at Dark Reading,  12/10/2019
Intel Issues Fix for 'Plundervolt' SGX Flaw
Kelly Jackson Higgins, Executive Editor at Dark Reading,  12/11/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
The Year in Security: 2019
This Tech Digest provides a wrap up and overview of the year's top cybersecurity news stories. It was a year of new twists on old threats, with fears of another WannaCry-type worm and of a possible botnet army of Wi-Fi routers. But 2019 also underscored the risk of firmware and trusted security tools harboring dangerous holes that cybercriminals and nation-state hackers could readily abuse. Read more.
Flash Poll
Rethinking Enterprise Data Defense
Rethinking Enterprise Data Defense
Frustrated with recurring intrusions and breaches, cybersecurity professionals are questioning some of the industrys conventional wisdom. Heres a look at what theyre thinking about.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-5252
PUBLISHED: 2019-12-14
There is an improper authentication vulnerability in Huawei smartphones (Y9, Honor 8X, Honor 9 Lite, Honor 9i, Y6 Pro). The applock does not perform a sufficient authentication in a rare condition. Successful exploit could allow the attacker to use the application locked by applock in an instant.
CVE-2019-5235
PUBLISHED: 2019-12-14
Some Huawei smart phones have a null pointer dereference vulnerability. An attacker crafts specific packets and sends to the affected product to exploit this vulnerability. Successful exploitation may cause the affected phone to be abnormal.
CVE-2019-5264
PUBLISHED: 2019-12-13
There is an information disclosure vulnerability in certain Huawei smartphones (Mate 10;Mate 10 Pro;Honor V10;Changxiang 7S;P-smart;Changxiang 8 Plus;Y9 2018;Honor 9 Lite;Honor 9i;Mate 9). The software does not properly handle certain information of applications locked by applock in a rare condition...
CVE-2019-5277
PUBLISHED: 2019-12-13
Huawei CloudUSM-EUA V600R006C10;V600R019C00 have an information leak vulnerability. Due to improper configuration, the attacker may cause information leak by successful exploitation.
CVE-2019-5254
PUBLISHED: 2019-12-13
Certain Huawei products (AP2000;IPS Module;NGFW Module;NIP6300;NIP6600;NIP6800;S5700;SVN5600;SVN5800;SVN5800-C;SeMG9811;Secospace AntiDDoS8000;Secospace USG6300;Secospace USG6500;Secospace USG6600;USG6000V;eSpace U1981) have an out-of-bounds read vulnerability. An attacker who logs in to the board m...