Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a3f4db88ac158b2…

MALICIOUS

PDF

74.6 KB Created: 2021-09-03 19:02:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9138e24147490ec13a21746ff48216fd SHA-1: 107040e968e91989a73d5a18184959bfbd1b5f45 SHA-256: 2a3f4db88ac158b207495353ca28038af4561d2e0cb0cac0f24530ddbff0a873
204 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. High-severity heuristics indicate it is a link farm pointing to compromised WordPress upload storage, likely serving as a lure to download a second-stage payload. The PDF itself does not contain readable content, but the presence of JavaScript and numerous external links strongly suggests a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/q0i7q3dpmbdkg9n5kd93odo1n8/47458858311.pdf In PDF document text
    • http://onsijsselstein.nl/userfiles/files/34230096386.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/jefazajojopike.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/1aigtj29psi2mpobjles2cfro4/povubomofategi.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/vmjummge1m2fss51vtpghp82im/37358631329.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/xerid.pdfIn PDF document text
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/shnt88t1m7uuqkg9bu17gi2ab1/zifetob.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160912336be34b---feneledotasekogataral.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/bafazawirazirepafifowobi.pdfIn PDF document text
    • https://mfdesign.hu/files/file/bavifasilofin.pdfIn PDF document text
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/saloxekibadubakozojezet.pdfIn PDF document text
    • http://grandinhr.eu/images/user/file/wovibawosazufogepawim.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/50c8792aca73ba434992a07645220652/11130301891.pdfIn PDF document text
    • http://eva.am/files/e41331e94e584384.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/janararunetotebe.pdfIn PDF document text
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/ff41fc159bde5c776de01e64ca3e1e1c/68876416650.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/jufamileniw.pdfIn PDF document text
    • https://kurek-rowery.pl/user_pict/file/bavez.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/068d2d8ad8099cf7959dacda9d8be1b0/fofotekenifusidofo.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/95720397143.pdfIn PDF document text
    • http://tubesealer.com/uploaded/file/1750311176612a2b12eaf02.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a81403c4aa2---42416727233.pdfIn PDF document text
    • http://brukbet.com/user_images/file/72859817754.pdfIn PDF document text
    • http://airholic.com/UpFiles/WebEditorFiles/file/kebimufagiweneganorunu.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/cb0b1513f76935d68a331c6110a99e8d/68670498611.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=plane+and+spherical+trigonometry+textbook+pdfPDF link annotation
    • https://mediacentre.heathrow.com/js/ckfinder/userfiles/files/kapozapasutelotuxuxi.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_off0000bfa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFA4 11516 bytes
SHA-256: 74c8ad3a2ee523bebe314ca83c86e436c62cebcf07002eb35a5d5b9b27b11347
font_01_sfnt_off0000da51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA51 16164 bytes
SHA-256: 376fd551887f9a313091b1d08e5d7905a6b0042275b03235cfb42ff6f366d97c
font_02_sfnt_off000103c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1