Attackers are increasingly exploiting the flexibility of Windows shortcut (.lnk) files, turning them into potent weapons for malware delivery.
According to recent telemetry, detected malicious LNK samples soared from 21,098 in 2023 to an alarming 68,392 in 2024 a spike of over 50%.
A technical investigation of 30,000 recent samples has revealed a sophisticated threat landscape, with LNK-based malware falling into four primary categories: exploit execution, file-on-disk execution, in-argument script execution, and overlay execution.
How LNK Files Are Abused
Windows LNK files, designed to provide quick access to files, folders, or applications, have become an attractive target for cybercriminals.
Their ability to execute content, conceal true file types, and use misleading icons makes them ideal for social engineering.
Malicious actors exploit this by crafting shortcut files that appear legitimate often masquerading as documents or trusted application links enticing users to click and inadvertently trigger malware.
At the core of LNK exploitation are three structural fields: LINKTARGET_IDLIST
, RELATIVE_PATH
, and COMMAND_LINE_ARGUMENTS
.
Analysis shows that over 99% of malicious LNK samples leverage the target resolution field, with the relative path and command-line arguments also commonly abused to stealthily execute payloads or commands.
These shortcuts may point directly to malware, use system tools as proxies to launch embedded threats, or pass complex scripts as arguments for interpreters like PowerShell or cmd.exe, often employing obfuscation to hinder detection.
Overlay execution marks a newer trend, where attackers append encoded or script-based payloads beyond the ‘legitimate’ end of an LNK file.
By combining this with clever command-line extraction such as using findstr
, mshta.exe
, or encoded PowerShell commands the malware can decode and execute embedded scripts or binaries.
Some variants exploit system vulnerabilities directly, such as the infamous CVE-2010-2568, using malformed header fields to trigger OS-level exploits simply by browsing to an infected folder.
Protection and Detection Strategies
According to the Report, LNK weaponization is now so prevalent that both enterprises and end-users need to be vigilant.
Users are advised to examine shortcut file properties closely right-clicking and checking if the target path or command-line appears suspicious.
Familiar icons and trusted names offer little assurance, as attackers consistently camouflage malicious shortcuts.
Palo Alto Networks and its partners in the Cyber Threat Alliance are responding with enhanced detection and defense measures.
Their next-generation firewalls, Prisma Access, and Cortex XDR products leverage cloud-delivered services and real-time machine learning to detect suspicious LNK patterns and block associated exploits, including those targeting legacy vulnerabilities.
Organizations suspecting compromise are urged to contact specialist incident response teams.
Indicators of Compromise (IOCs)
No. | SHA256 Hash |
---|---|
1 | a90c87c90e046e68550f9a21eae3cad25f461e9e9f16a8991e2c7a70a3a59156 |
2 | 08233322eef803317e761c7d380d41fcd1e887d46f99aae5f71a7a590f472205 |
3 | 9d4683a65be134afe71f49dbd798a0a4583fe90cf4b440d81eebcbbfc05ca1cd |
4 | a89b344ac85bd27e36388ca3a5437d8cda03c8eb171570f0d437a63b803b0b20 |
5 | 28fa4a74bbef437749573695aeb13ec09139c2c7ee4980cd7128eb3ea17c7fa8 |
6 | fb792bb72d24cc2284652eb26797afd4ded15d175896ca51657c844433aba8a9 |
7 | f585db05687ea29d089442cc7cfa7ff84db9587af056d9b78c2f7a030ff7cd3d |
8 | b2fd04602223117194181c97ca8692a09f6f5cfdbc07c87560aaab821cd29536 |
9 | 86f504dea07fd952253904c468d83d9014a290e1ff5f2d103059638e07d14b09 |
10 | d1dc85a875e4fc8ace6d530680fdb3fb2dc6b0f07f892d8714af472c50d3a237 |
11 | 76d2dd21ffaddac1d1903ad1a2b52495e57e73aa16aa2dc6fe9f94c55795a45b |
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