Malicious PDF — malware analysis report

Static analysis result for SHA-256 521d943b6021cb17…

MALICIOUS

PDF

85.9 KB Created: 2021-07-06 10:04:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: dda1a7f48c3ae370b3797ceef94d1228 SHA-1: 1cac7acd1a83a7b7a0868216b23c0e4cc4976750 SHA-256: 521d943b6021cb1708123066618c59ecd7d159b48198cf16878677222dec0700
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079165bc1313---xoxutozivile.pdf In PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160c7980996794---58097960348.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609d81facfff1---84039449558.pdfIn PDF document text
    • http://doublehappyvstheinfinitesadness.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5fdb8c8d4e---36299940235.pdfIn PDF document text
    • http://isystem.hu/ckfinder/userfiles/files/19587646474.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ce3b04900---85242671305.pdfIn PDF document text
    • http://clinicaveterinariaalbese.eu/userfiles/files/88781505883.pdfIn PDF document text
    • https://dodatnagarancija.com/userfiles/file/50124670663.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c9407522b9a---71829015386.pdfIn PDF document text
    • http://webinaris.biz/ckfinder/userfiles/publics/files/26836591582.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/8887536284.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085e148369e7---vural.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bbaa087197c---97483172729.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079e2c7968fa---80223220489.pdfIn PDF document text
    • http://texmet.pl/userimages/file/33454071430.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/7eb5ae8c65ac5bad11fd525ede2e10f3/13319617368.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d370cb3b718---pibevexetalabe.pdfIn PDF document text
    • http://erbilsunhotel.com/wp-content/plugins/super-forms/uploads/php/files/5td6e5tr6i8pnn3qbdjga1fgp5/xumimulako.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/721f0ca6e4fc9d8c353e0b1d1d6d10f6/26738062941.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607934f930db3---67350682847.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c0328fce60f---wirebonamaguzewujib.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4bdbe949d---siwiradesoj.pdfIn PDF document text
    • http://guchenes.com/d/files/25448551624.pdfIn PDF document text
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0103f3b3b2---jozakubovefexunodepu.pdfIn PDF document text
    • http://www.fk-fudosan.net/app/webroot/img/userfiles/files/ronirado.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=kreator+lion+with+eagle+wingsPDF 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_off0000e18d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE18D 23616 bytes
SHA-256: 8aa7a16ecac2183062066d798d8149417ba3316debdfb2866d6eccda86a9ebba
font_01_sfnt_off00011a7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A7C 10464 bytes
SHA-256: d7f290cc35cbb8cebcea0031fb69362bb489a96c6907cf19bfac9cf95b5aaec1
font_02_sfnt_off0001323a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1323A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1