Magniber ransomware now infects Windows users via JavaScript files

A recent malicious campaign delivering Magniber ransomware has been targeting Windows home users with fake security updates.

Threat actors created in September websites that promoted fake antivirus and security updates for Windows 10. The downloaded malicious files (ZIP archives) contained JavaScript that initiated an intricate infection with the file-encrypting malware.

A report from HP’s threat intelligence team notes that Magniber ransomware operators demanded payment of up to $2,500 for home users to receive a decryption tool and recover their files. The strain focuses explicitly on Windows 10 and Windows 11 builds.

In April 2022, Magniber was seen distributed as a Windows 10 update via a network of malicious websites. 

In January, the its operators used Chrome and Edge browser updates to push malicious Windows application package files (.APPX).

Magniber’s new infection chain

In previous campaign, the threat actor used MSI and EXE files. For the recent on, it switched to JavaScript files that had the following names:

• SYSTEM.Critical.Upgrade.Win10.0.ba45bd8ee89b1.js
• SYSTEM.Security.Database.Upgrade.Win10.0.jse
• Antivirus_Upgrade_Cloud.29229c7696d2d84.jse
• ALERT.System.Software.Upgrade.392fdad9ebab262cc97f832c40e6ad2c.js

These files are obfuscated and use a variation of the “DotNetToJScript” technique to execute a .NET file in the system memory, lowering the risk of detection by antivirus products available on the host.

The .NET file decodes shellcode that uses its own wrapper to make stealthy syscalls, and injects it into a new process before terminating its own.

The shellcode deletes shadow copy files via WMI and disables backup and recovery features through “bcdedit” and “wbadmin.” This increases the chances of getting paid as victims have one less option to recover their files.

To perform this action, Magniber uses a bypass for the User Account Control (UAC) feature in Windows.

It relies on a mechanism that involves creating of a new registry key that allows specifying a shell command. In a later step, the “fodhelper.exe” utility is executed to run a script for deleting the shadow copies.

Finally, Magniber encrypts the files on the host and drops the ransom notes containing instructions for the victim to restore their files.

HP’s analysts noticed that while Magniber attempts to limit the encryption only to specific file types, the pseudohash it generates during the enumeration isn’t perfect, which results in hash collisions and “collateral damage”, i.e., encrypting non-targeted file types as well.

Home users can defend against a ransomware attack by making regular backups for their files and to keep them on an offline storage device. This allows recovery of the data onto a freshly installed operating system.

Before restoring the data, users should make sure tha their backups were not been infected.

Finally, the ransomware tells the victim about what happened and how they can decrypt their data by dropping an HTML ransom note in every directory that contains an encrypted file. To make sure the user sees the demand, Magniber also opens the note in a web browser.

Figure 10 – Magniber ransom note

HOW TO PROTECT YOURSELF

Home users can protect themselves from ransomware campaigns like this one by following this simple advice:

• Follow the principle of least privilege by only using administrator accounts if you really need to. Many home users have administrator privileges but rarely need them.
• Download software updates from trusted sources. The campaign depends on tricking people into opening fake software updates. Only download updates from trustworthy sources such as Windows Update and official software vendor websites.
• Back up your data regularly. Backing up your data will give you peace of mind should the worst happen.

CONCLUSION

Even though Magniber does not fall into the category of Big Game Hunting, it can still cause significant damage. Home users were the likely target of this malware based on the supported operating system versions and UAC bypass. The attackers used clever techniques to evade protection and detection mechanisms. Most of the infection chain is “fileless”, meaning the malware only resides in memory, reducing the chances of it being detected. Magniber also bypasses detection techniques that rely on user-mode hooks because it uses syscalls instead of standard Windows API libraries. With the UAC bypass, the malware deletes the infected system’s shadow copy files and disables backup and recovery features, preventing the victim from recovering their data using Windows tools.

INDICATORS OF COMPROMISE (IOCS)

Reference Magniber JavaScript sample used for our analysis:
934cfeb5ee3d2ba49831d76dffb1a2658326e1cd90b50779d6670eb2fbdc7ed1

Magniber JavaScript files:
6155453a58b0ba360fd18a32d838c4452fec374c364824b50447500c8fd12e80
5b2a5ac50977f41ac27590395bb89c1afd553e58f2979b680d545bff1530a17b
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dfa32d8ed7c429b020c0581148a55bc752c35834d7a2b1bae886f2b436285c94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c0bf9153ce1641791b357fdb5c2c596fbbf15991a86f510cc444bdb477574d44
bf50794c33eebc9dc2ce3902fe29f683a37da50de3654a2775baa74d0bbd1188
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cc1ce8c687450b082dd19a6c5d868f5798e52422172f91ee4b70cb5ffd9f6fcd
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6b18a287aa2c170605409a4675fd600d0597623d174445aaea5a2279bee0c145
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123d7744a407af376b4ee4402ff8bee588b40540bcfba22fb64768d1de8c1861

Magniber encrypts files with these extensions:
{
“1”: [“c”, “h”, “j”, “p”, “x”],

“2”: [“ai”, “ca”, “cd”, “cf”, “cs”, “ct”, “db”, “dd”, “dt”, “dv”, “dx”, “em”, “ep”, “eq”, “fa”, “fb”, “fi”, “fo”, “gv”, “hp”, “hs”, “hz”, “ib”, “ii”, “js”, “jw”, “ma”, “mb”, “me”, “mm”, “mx”, “my”, “of”, “pa”, “pm”, “pu”, “px”, “qd”, “rb”, “rd”, “rs”, “rt”, “rw”, “sh”, “sq”, “st”, “te”, “tm”, “vb”, “vm”, “vw”, “wn”, “wp”, “xd”, “ya”, “ym”, “zw”],

“3”: [“hpi”, “icn”, “idc”, “idx”, “igt”, “igx”, “ihx”, “iiq”, “ocr”, “abm”, “abs”, “abw”, “act”, “adn”, “adp”, “aes”, “aft”, “afx”, “agp”, “ahd”, “aic”, “aim”, “alf”, “ans”, “apd”, “apm”, “aps”, “apt”, “apx”, “art”, “arw”, “asc”, “ase”, “ask”, “asm”, “asp”, “asw”, “asy”, “aty”, “awp”, “awt”, “aww”, “azz”, “bad”, “bay”, “bbs”, “bdb”, “bdp”, “bdr”, “bib”, “bmx”, “bna”, “bnd”, “boc”, “bok”, “brd”, “brk”, “brn”, “brt”, “bss”, “btd”, “bti”, “btr”, “can”, “cdb”, “cdc”, “cdg”, “cdr”, “cdt”, “cfu”, “cgm”, “cin”, “cit”, “ckp”, “cma”, “cmx”, “cnm”, “cnv”, “cpc”, “cpd”, “cpg”, “cpp”, “cps”, “cpx”, “crd”, “crt”, “crw”, “csr”, “csv”, “csy”, “cvg”, “cvi”, “cvs”, “cvx”, “cwt”, “cxf”, “cyi”, “dad”, “daf”, “dbc”, “dbf”, “dbk”, “dbs”, “dbt”, “dbv”, “dbx”, “dca”, “dcb”, “dch”, “dcr”, “dcs”, “dct”, “dcx”, “dds”, “ded”, “der”, “dgn”, “dgs”, “dgt”, “dhs”, “dib”, “dif”, “dip”, “diz”, “djv”, “dmi”, “dmo”, “dnc”, “dne”, “doc”, “dot”, “dpp”, “dpx”, “dqy”, “drw”, “drz”, “dsk”, “dsn”, “dsv”, “dta”, “dtw”, “dvi”, “dwg”, “dxb”, “dxf”, “eco”, “ecw”, “ecx”, “edb”, “efd”, “egc”, “eio”, “eip”, “eit”, “emd”, “emf”, “epf”, “epp”, “eps”, “erf”, “err”, “etf”, “etx”, “euc”, “exr”, “faq”, “fax”, “fbx”, “fcd”, “fcf”, “fdf”, “fdr”, “fds”, “fdt”, “fdx”, “fes”, “fft”, “fic”, “fid”, “fif”, “fig”, “flr”, “fmv”, “fpt”, “fpx”, “frm”, “frt”, “frx”, “ftn”, “fxc”, “fxg”, “fzb”, “fzv”, “gdb”, “gem”, “geo”, “gfb”, “ggr”, “gih”, “gim”, “gio”, “gpd”, “gpg”, “gpn”, “gro”, “grs”, “gsd”, “gtp”, “gwi”, “hbk”, “hdb”, “hdp”, “hdr”, “hht”, “his”, “hpg”, “htc”, “hwp”, “ibd”, “imd”, “ink”, “ipf”, “ipx”, “itw”, “iwi”, “jar”, “jas”, “jbr”, “jia”, “jis”, “jng”, “joe”, “jpe”, “jps”, “jpx”, “jsp”, “jtf”, “jtx”, “jxr”, “kdb”, “kdc”, “kdi”, “kdk”, “kes”, “key”, “kic”, “klg”, “knt”, “kon”, “kpg”, “kwd”, “lay”, “lbm”, “lbt”, “ldf”, “lgc”, “lis”, “lit”, “ljp”, “lmk”, “lnt”, “lrc”, “lst”, “ltr”, “ltx”, “lue”, “luf”, “lwo”, “lwp”, “lws”, “lyt”, “lyx”, “lzf”, “mac”, “man”, “map”, “maq”, “mat”, “max”, “mbm”, “mdb”, “mdf”, “mdn”, “mdt”, “mef”, “mel”, “mft”, “min”, “mnr”, “mnt”, “mos”, “mpf”, “mpo”, “mrg”, “msg”, “mud”, “mwb”, “mwp”, “myd”, “myi”, “ncr”, “nct”, “ndf”, “nef”, “nfo”, “njx”, “nlm”, “now”, “nrw”, “nsf”, “nyf”, “nzb”, “obj”, “oce”, “oci”, “odb”, “odg”, “odm”, “odo”, “odp”, “ods”, “odt”, “oft”, “omf”, “oqy”, “ora”, “orf”, “ort”, “orx”, “ost”, “ota”, “otg”, “oti”, “otp”, “ots”, “ott”, “ovp”, “ovr”, “owc”, “owg”, “oyx”, “ozb”, “ozj”, “ozt”, “pan”, “pap”, “pas”, “pbm”, “pcd”, “pcs”, “pdb”, “pdd”, “pdf”, “pdm”, “pds”, “pdt”, “pef”, “pem”, “pff”, “pfi”, “pfs”, “pfv”, “pfx”, “pgf”, “pgm”, “phm”, “php”, “pic”, “pix”, “pjt”, “plt”, “pmg”, “pni”, “pnm”, “pnz”, “pop”, “pot”, “ppm”, “pps”, “ppt”, “prt”, “prw”, “psd”, “pse”, “psp”, “pst”, “psw”, “ptg”, “pth”, “ptx”, “pvj”, “pvm”, “pvr”, “pwa”, “pwi”, “pwr”, “pxr”, “pza”, “pzp”, “pzs”, “qmg”, “qpx”, “qry”, “qvd”, “rad”, “ras”, “raw”, “rcu”, “rdb”, “rft”, “rgb”, “rgf”, “rib”, “ric”, “ris”, “rix”, “rle”, “rli”, “rng”, “rpd”, “rpf”, “rpt”, “rri”, “rsb”, “rsd”, “rsr”, “rst”, “rtd”, “rtf”, “rtx”, “run”, “rzk”, “rzn”, “saf”, “sam”, “sbf”, “scc”, “sch”, “sci”, “scm”, “sct”, “scv”, “scw”, “sdb”, “sdf”, “sdm”, “sdw”, “sep”, “sfc”, “sfw”, “sgm”, “sig”, “skm”, “sla”, “sld”, “slk”, “sln”, “sls”, “smf”, “sms”, “snt”, “sob”, “spa”, “spe”, “sph”, “spj”, “spp”, “spq”, “spr”, “sqb”, “srw”, “ssa”, “ssk”, “stc”, “std”, “sti”, “stm”, “stn”, “stp”, “str”, “stw”, “sty”, “sub”, “suo”, “svf”, “svg”, “sxc”, “sxd”, “sxg”, “sxi”, “sxm”, “sxw”, “tab”, “tcx”, “tdf”, “tdt”, “tex”, “thp”, “tlb”, “tlc”, “tmd”, “tmv”, “tmx”, “tne”, “tpc”, “trm”, “tvj”, “udb”, “ufr”, “unx”, “uof”, “uop”, “uot”, “upd”, “usr”, “vbr”, “vbs”, “vct”, “vdb”, “vdi”, “vec”, “vmx”, “vnt”, “vpd”, “vrm”, “vrp”, “vsd”, “vsm”, “vue”, “wbk”, “wcf”, “wdb”, “wgz”, “wks”, “wpa”, “wpd”, “wpg”, “wps”, “wpt”, “wpw”, “wri”, “wsc”, “wsd”, “wsh”, “wtx”, “xar”, “xdb”, “xlc”, “xld”, “xlf”, “xlm”, “xls”, “xlt”, “xlw”, “xps”, “xwp”, “xyp”, “xyw”, “ybk”, “zdb”, “zdc”],

“4”: [“agif”, “albm”, “apng”, “awdb”, “bean”, “cals”, “cdmm”, “cdmt”, “cdmz”, “cimg”, “clkw”, “colz”, “djvu”, “docb”, “docm”, “docx”, “docz”, “dotm”, “dotx”, “dtsx”, “emlx”, “epsf”, “fdxt”, “fodt”, “fpos”, “fwdn”, “gcdp”, “gdoc”, “gfie”, “glox”, “grob”, “gthr”, “icon”, “icpr”, “idea”, “info”, “itdb”, “java”, “jbig”, “jbmp”, “jfif”, “jrtf”, “kdbx”, “mbox”, “mgcb”, “mgmf”, “mgmt”, “mgmx”, “mgtx”, “mmat”, “mrxs”, “oplc”, “pano”, “pict”, “pjpg”, “pntg”, “pobj”, “potm”, “potx”, “ppam”, “ppsm”, “ppsx”, “pptm”, “pptx”, “psdx”, “psid”, “rctd”, “riff”, “scad”, “sdoc”, “sldm”, “sldx”, “svgz”, “text”, “utxt”, “vsdm”, “vsdx”, “vstm”, “vstx”, “wire”, “wmdb”, “xlgc”, “xlsb”, “xlsm”, “xlsx”, “xltm”, “xltx”, “zabw”],

“5”: [“accdb”, “class”]
}

Magniber domains:
totwo[.]pw
ittakes[.]fun
catat[.]site
tinpick[.]online
pirlay[.]fun
buyaims[.]online
orhung[.]space
actsred[.]site