Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f4042d166622f21…

MALICIOUS

PDF

93.1 KB Created: 2021-07-17 15:57:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8ecb13214f371048db8b96b982ab340a SHA-1: 8a0b1ff96d8f9f63699998b44356432f50615410 SHA-256: 8f4042d166622f21e821a3836efb6477dbf011fb86ed31e8c5a14ec4876be136
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it contains embedded JavaScript and links to compromised WordPress upload storage. The PDF structure and numerous external links suggest it functions as a link farm, directing users to potentially malicious sites for phishing or further payload delivery. The embedded JavaScript is likely used to facilitate these redirects or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160710314a3bac---sibibafewo.pdf
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607686195524f---81650669190.pdf
    • http://ajivikafinance.com/userfiles/file/wanetujadefu.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/e2sjnk80f6s6iofdvoc866str0/29819768104.pdf
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/b9ujlagc5ekck5laf9e83iq8ub/voxujedutosimirujopajow.pdf
    • http://tandprotheses.com/ckfinder/userfiles/files/1924714714.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb49955eae---bidusutarumapupi.pdf
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089abb583ffc---96880370938.pdf
    • http://rheinmotel.com/userfiles/file/96366815947.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608937c253120---bupilumijinuwamunuga.pdf
    • http://hncastlecable.com/d/files/domubatobidujatiz.pdf
    • http://shreyaghoshal.com/konadnew/userfiles/file/87019410590.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/5f09de2dbe09adb160a2b4e8ac5b23e3/vixir.pdf
    • https://eurouniversal.eu/ckfinder/userfiles/files/kuwowijuzavevovakarepiwa.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/ebaaadjnmm7duniu72j6shvq75/54667143521.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160e9439784e77---savakar.pdf
    • http://www.leads-bd.org/app/webroot/js/ckfinder/userfiles/files/rawuzuloxefifobuwiwinu.pdf
    • http://lbhs1965.com/clients/6/6b/6bdd8f708684a1f547efbf97e1630fe5/File/1578463242.pdf
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/4cp10tc7n72o4riiiq0qcbpi3c/xudimedoworasopuvoz.pdf
    • http://wecans.net/_UploadFile/Images/file/93894440042.pdf
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/b8407dea4f7104702b30c047cdcadc7b/56590468837.pdf
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/5ga2ebv9j58ejb1ktepiheceh6/61543504430.pdf
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/39c215472aa7d5206edb4d4bbf4c3f52/76225458235.pdf
    • https://rolcsi-bau.hu/userfiles/files/patitixefiso.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=the+4+states+of+matter
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ac4.bin
4934a1f5bef6fbf404ae1771dc5a0dd1b14ebb1b65150d69f51076e71742ea31
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AC4 10276 bytes
font_01_sfnt_off000121fc.bin
c1e4776c624f8bdf81ea3b36a4d91183c3f4b8bc5072d8fb6f566e9b16adfc05
pdf-font-stream PDF embedded font (sfnt) at offset 0x121FC 17248 bytes
font_02_sfnt_off00014f21.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14F21 16792 bytes