Malicious PDF — malware analysis report

Static analysis result for SHA-256 1fb4b1a4504e2a87…

MALICIOUS

PDF

71.3 KB Created: 2021-09-18 16:45:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6a74e75f483bc86dca26aa6e6e94b639 SHA-1: 26ead9991a490fee08ceb31581426bf6ac0f0e99 SHA-256: 1fb4b1a4504e2a8703cd24184653f2bb2913a776eae65b638670857fd0c63da7
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded JavaScript likely facilitates the redirection to these malicious sites, which in turn may serve phishing content or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://medvor.ru/uplcv?utm_term=how+to+recover+deleted+contact+in+android PDF link annotation
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/1d5c21681275b90c29a1890366aa2c30/63315082346.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/f4b1d85738e322436cb1c5960ff2c25d/xawenobewafoj.pdfIn PDF document text
    • http://funagamex.vn/PhuongNamGroup/userfiles/files/43437913305.pdfIn PDF document text
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/mogituwu.pdfIn PDF document text
    • https://grupo-kayros.com/userfiles/file/xojugififem.pdfIn PDF document text
    • http://www.cda.org.hk/ckfinder/userfiles/files/papigujoka.pdfIn PDF document text
    • https://hippodrome-compiegne.fr/www/uploads/file/15637891932.pdfIn PDF document text
    • http://cathugo-yachts.de/res/wysiwyg/file/90752070899.pdfIn PDF document text
    • https://inprovitcaribe.com/ckfinder/userfiles/files/25405963606.pdfIn PDF document text
    • https://kohphanganhotelandtour.com/userfiles/file/1557260355.pdfIn PDF document text
    • http://dakov.hu/_user/file/xolugixigijukivixap.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c79e92c5b5---13465546791.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/zipopititagesam.pdfIn PDF document text
    • https://store-connector.com/_upload_bilder/_filemanager/file/puwefifipepajigojebibujen.pdfIn PDF document text
    • http://mobitransjogja.com/files/94633013746.pdfIn PDF document text
    • http://amongelite.com/ci/userfiles/files/68877796015.pdfIn PDF document text
    • http://car-zone.sk/data/data/file/13577180245.pdfIn PDF document text
    • https://mb-classic-service.de/userfiles/file/980846080.pdfIn PDF document text
    • http://aescantabria.es/upload/fckeditor/file///nuxavusoxuwazoloxawiris.pdfIn PDF document text
    • http://labradory.pl/file/xiresakinijapoxeriki.pdfIn PDF document text
    • http://veszpremlizards.hu/_user/file/32522489110.pdfIn PDF document text
    • https://astefin.ro/ckfinder/userfiles/files/16062383080.pdfIn PDF document text
    • http://hoangminhsaigon.vn/@dmin/js/ckfinder/userfiles/files/zedin.pdfIn PDF document text
    • http://terralis.eu/catalogue_dynamique/file/64063283473.pdfIn PDF document text
    • http://tiszaikaland.hu/upload/file/64046285783.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_off0000b72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB72C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cf3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3E 16012 bytes
SHA-256: b77c171f1bab0ab09d52194e84a7e3ef9175de7d99d11b571c5cbdcfde5562f0
font_02_sfnt_off0000f830.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF830 10336 bytes
SHA-256: e49655fb8e1d64c666a6f886876c93be911a9a9654eeee5bfa950ae5643e1789