Malicious PDF — malware analysis report

Static analysis result for SHA-256 4117e8f314620405…

MALICIOUS

PDF

83.7 KB Created: 2021-08-23 13:54:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-22
MD5: c20ad6c65da5a710f27720ef1c392af8 SHA-1: 590bfc98834a8aae89ad1c2308612f31218e615d SHA-256: 4117e8f314620405533565adcdeb4164fbefd35d67fe555a062ef8dde113ab2b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous compromised WordPress upload directories, indicating a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic confirm the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • 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.
  • 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 http://hajnysport.cz/FCK_userfiles/file/11076282271.pdf In PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/dd78e486a228b9e6fe99ee09dbdf9af8/ruvuvepizojevamizigebo.pdfIn PDF document text
    • https://agenciaboom.com/wp-content/plugins/super-forms/uploads/php/files/grvhgv64334tvsqm1icrb352l5/xeziliwir.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/g2gcurfkjasec6ith3esddpn61/23477843923.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/73726372251.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072fd5835549---wiladugu.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097f64465941---6443553217.pdfIn PDF document text
    • http://florylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/pavabuwesores.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/uee2m13v2rqfi7omt0ui9ob49m/retavuramew.pdfIn PDF document text
    • http://9meclinic.com/ckfinder/userfiles/files/mafitoposovepozuse.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bde181bf77---81615422505.pdfIn PDF document text
    • http://iswii.net/ckfinder/userfiles/files/lalirijosuvajokipit.pdfIn PDF document text
    • http://veivel.com/userfiles/file/nizusilabupib.pdfIn PDF document text
    • http://neo-net.info/giganet/files/file/nefutul.pdfIn PDF document text
    • http://studioarchoggianiepartners.it/userfiles/files/fuxif.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/dofiwuxifurot.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/899c4d797fbb4e979268d9b0235fef0a/biwudoravizararubewiguwu.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/wogufetukokanefami.pdfIn PDF document text
    • https://sdyh.gr/wp-content/plugins/super-forms/uploads/php/files/vq3p82budc9l27sr117o44m526/20803091022.pdfIn PDF document text
    • http://congtrinhnhaviet.vn/upload/files/14546866049.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/gexajuxipujutuwavaw.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/fetuziminejisatotolir.pdfIn PDF document text
    • http://dztechfin.com/upload/file///20841684263.pdfIn PDF document text
    • https://china-glass-mosaic.com/userfiles/files/20210613_072858.pdfIn PDF document text
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/37821356200.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=acellus+world+history+answersPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9fd9a54db1---79406902579.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dfb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7D0 10748 bytes
SHA-256: 0f0d90b7ea175e181bff884ba13617f7c2bd2a41d8311e70ce376cdead2fb89d
font_02_sfnt_off000110a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110A0 18488 bytes
SHA-256: 05ed4b84f29e56eead08dcfe7a63b9c0341d78b9a0101be82fda6f187e275080