Malicious PDF — malware analysis report

Static analysis result for SHA-256 b571bdaa1a340300…

MALICIOUS

PDF

69.5 KB Created: 2021-09-26 08:52:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b150ac9bd8a35d1720991b5ac08048e7 SHA-1: b9ec140ec55fdde2e55fe26742d7f5d19e8b778e SHA-256: b571bdaa1a340300aad544b8a2043012e50ab65d1881a65b3ea80cea3532f61f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the embedded URLs are the primary indicators of compromise, likely leading to a malicious second-stage payload or phishing page.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133037be10ae---8316947284.pdf In PDF document text
    • http://acm-medicali.it/userfiles/files/74295958937.pdfIn PDF document text
    • https://gz-topstar.com/wp-content/plugins/super-forms/uploads/php/files/17d260cbb4e5a43c3ab8d2bc7f6dea5d/tebunijevi.pdfIn PDF document text
    • http://princeworldwide.com/multimedia/userfiles/file/77499483801.pdfIn PDF document text
    • http://remaining-mc.de/userfiles/file/30956651878.pdfIn PDF document text
    • https://www.fyna.com.au/application/third_party/ckfinder/userfiles/files/kedujupimokemofino.pdfIn PDF document text
    • http://pphjako.pl/userfiles/file/pewisewopujujududajesi.pdfIn PDF document text
    • https://letajicikoberce.cz/userfiles/file/55307055176.pdfIn PDF document text
    • https://hotararicedo.ro/files/files/nujipodowerunaruj.pdfIn PDF document text
    • http://sanarina-coaching.de/ckfinder/userfiles/files/pokuzigivikibunazaguk.pdfIn PDF document text
    • https://oxi-dental.ro/imagini_ws/pejabano.pdfIn PDF document text
    • http://cmtoolsrental.com/user_img/files/7178158431.pdfIn PDF document text
    • https://aydin-elektrik.com/resimler/files/wenusokuveximax.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/5292211973.pdfIn PDF document text
    • http://saigondome.com/uploads/userfiles/file/32478945670.pdfIn PDF document text
    • http://yourtruck.be/upload/ckeditor/file/jifiraf.pdfIn PDF document text
    • http://kamnitikamini.si/upload/files/56729282439.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/78794014914.pdfIn PDF document text
    • http://ivankotov.ru/img/lib/file/21664230005.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/zamiwimegox.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614fd28511195---livufidusutok.pdfIn PDF document text
    • https://ofcourselc.com/admin/uploadsfile/tetugoxodud.pdfIn PDF document text
    • http://serbanindustrialconstruct.ro/uploads/files/27438686089.pdfIn PDF document text
    • http://xn--80aaaaadfwa5aftjhxrkcrg8iwc.xn--p1ai/pict/file/33650652613.pdfIn PDF document text
    • https://sistemagestiondpr.com/userfiles/file/durijivo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=morefit+app+for+androidPDF 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_off0000b325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB325 15104 bytes
SHA-256: 3099af156a94075f3a1fa2cfdd3c5e0f81e8b4a4a1269a93795fb09424912d44
font_01_sfnt_off0000d8c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C8 10268 bytes
SHA-256: d7711672401d4b0d0ef9f8b5427be84cd0f7e825c7fac5d4a487a9f82855071e
font_02_sfnt_off0000effa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1