Malicious PDF — malware analysis report

Static analysis result for SHA-256 941f55534c1f668c…

MALICIOUS

PDF

88.6 KB Created: 2021-08-25 12:22:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 6129f96bcbe37a7c26ff3f41220305cf SHA-1: bfdd4f21327b808988532a9d9e6919e92cd4f20a SHA-256: 941f55534c1f668cabeb83bcf401208bef98f76475461605659b5a269b879b5a
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, likely serving as a lure to download further malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically a phishing or trojan payload. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to distribute malware via malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610bbf1d13f62---lotosamometun.pdf In PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/nutitee2gt5j4i313jcvo0780h/1598432058.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/c07hip0kp1u0t065jktih4j880/52126688819.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/6a06b256ed440d1a6d5db484d3bf0052/potewez.pdfIn PDF document text
    • https://tkpmission.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a8d8f415bc8---75270814393.pdfIn PDF document text
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/b2026afec703ae184ccb962a19739a64/gutaketoroledalobededo.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609039f89659b---34188009726.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160cafcd1082e5---lukot.pdfIn PDF document text
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16080b2b0b08b3---sopajotakejokodarodosa.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160aa08afc8a6f---95895237751.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d32186c520---45109055753.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092e18c61568---xifubijevukaf.pdfIn PDF document text
    • http://studiotecnicobonoli.com/userfiles/files/46467688570.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/5abb3acb151ba37c5a247112e7471fd9/38610135085.pdfIn PDF document text
    • https://tch.lu/files/files/96707932615.pdfIn PDF document text
    • http://trekkingsapatours.com/upload/files/wejibidob.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160866828b38a1---kigafozezimimiseji.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/zabotopomidewiwemumezu.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c56aab4e65f---wupalitixujad.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/ledunak.pdfIn PDF document text
    • https://www.assofmt.org/ckfinder/userfiles/files/vasowujetolerozidakatose.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/5026339024.pdfIn PDF document text
    • https://www.reflectionuk.com/wp-content/plugins/super-forms/uploads/php/files/f338cm3ghcfadojpme9eq5ujrm/25048213011.pdfIn PDF document text
    • https://agatanorek.com/files/file/liwetututitosibalulo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=starch+structure+and+functionPDF link annotation
    • 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_off0000fa61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA61 16036 bytes
SHA-256: e0b06129fc748e138b5d1670ad8201fad3ac990bdaa732165c7dad99116aa557
font_01_sfnt_off000123bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013bd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BD6 10704 bytes
SHA-256: 1e36ecf6c7464bae3b45f7da353cb2030049353a9c69f6097c7c2d4fae1bd9fa

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