Malicious PDF — malware analysis report

Static analysis result for SHA-256 329eb99a803204a9…

MALICIOUS

PDF

87.0 KB Created: 2021-09-13 15:15:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 313e69a3cc1340d56741e6a979a4856a SHA-1: df63c345d27e31330f502e7014dad1c095acaa6a SHA-256: 329eb99a803204a9e9b9a57d2a16c03222ade427cf5d4fe34021e69646c752d4
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The `wkhtmltopdf` authoring application is unusual for a malicious PDF, but the overall structure and URL distribution strongly indicate a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

Heuristics 6

  • 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 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://queure.ru/uplcv?utm_term=putlocker+zombieland+double+tap PDF link annotation
    • http://bjqyms.com/filespath/files/20210908182700.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/zaradadideponidolaz.pdfIn PDF document text
    • http://changwontour.kr/FileData/ckfinder/files/20210904_64FDF38CABF983F9.pdfIn PDF document text
    • http://dioblina.eu/userfiles/file/finupideligudabuki.pdfIn PDF document text
    • http://df-2.de/images/daten/file/wuzanodo.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/pj5tjqke2ge3t6uqv5fbohlmk4/24839302660.pdfIn PDF document text
    • http://silarperu.com/UserFiles/file/74761655215.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/loregugiba.pdfIn PDF document text
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/161395ce61900f---fefuzebegike.pdfIn PDF document text
    • https://pataniforum.com/admin/jquery/ckfinder/userfiles/files/belitegeno.pdfIn PDF document text
    • http://stainless-faucet.com/uploads/htmlupload/files/97345143007.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/fjlmpvkj8br76j5mqf78i6gr56/bavusosutonoxoguw.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/3e91994fe107ba0fde70848699096529/tafavinud.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/femejexa.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/afgpocur5tqfhp65d53hss5o7l/xotiguwekarejubo.pdfIn PDF document text
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/sexuzezusofugipegonodijik.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/db231a551fc2da6a519df701f782d758/zadoxepajorokor.pdfIn PDF document text
    • https://trouver-une-ssii.com/img/pics/files/jalidafaweguko.pdfIn PDF document text
    • http://clubselectionvoyages.net/images/file/gokidadirexutigiroxunuw.pdfIn PDF document text
    • http://siltherm.com/ckfinder/userfiles/files/wesekuzuzi.pdfIn PDF document text
    • https://ensegun2.com/ckfinder/userfiles/files/91907596051.pdfIn PDF document text
    • http://massarentearchitettura.com/userfiles/files/dapivoluravezo.pdfIn PDF document text
    • http://ifaistos.reality.gr/~triantaf/images/file/kulekisarazew.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_off0000eb0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB0D 10900 bytes
SHA-256: 6c4d3a51d92c75b47126bf3f6e8896452ee9993c3f39d7ccb85d937eeb270573
font_01_sfnt_off00010414.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10414 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011c26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C26 19304 bytes
SHA-256: 7774cc26ff8a73a1420ead5110531e6e10ee740da336b9a5421e46c0b31fb577

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