Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0c4301d053345e8…

MALICIOUS

PDF

74.5 KB Created: 2021-09-06 21:19:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d39920277a4deb0e665286e1a36bbdea SHA-1: 250e390f50ef355fbef6697bc9de226f7c676b21 SHA-256: a0c4301d053345e8d6580701138afbddf8e7a3433fb1afb136b9266fff46be00
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and link farms pointing to potentially compromised websites, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document designed to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://synerhu.ru/uplcv?utm_term=biosensors+for+medical+applications+pdf PDF link annotation
    • https://marmarases.com/upload/ckfinder/files/37779695978.pdfIn PDF document text
    • https://carsen.sk/editor_uploads/system/files/xorij.pdfIn PDF document text
    • http://kristiankutschera.de/userfiles/file/kofonumodisirafibe.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210816130711.pdfIn PDF document text
    • http://landia-print.com/pdir/file/27933907297.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a4e123b6021---90880437130.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077ac7a0ad40---sivinepekekakodipatomu.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f9960b5898---72157668020.pdfIn PDF document text
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/1c5d27302bdc1d99b1140475968a6365/8593146744.pdfIn PDF document text
    • http://multiseal.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160c158b9cb5dc---22862308457.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/juxozera.pdfIn PDF document text
    • https://rubin2000-distribuitorshop.ro/userfiles/file/zunagupawefux.pdfIn PDF document text
    • https://lanna-flyingclub.com/ckfinder/userfiles/files/masididofakononez.pdfIn PDF document text
    • http://eska-lift.ru/userfiles/file/11538290701.pdfIn PDF document text
    • http://barexkft.hu/userfiles/file/65560378889.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c262768b3e1---46888186711.pdfIn PDF document text
    • https://nepalaviationmuseum.com/userfiles/files/21928200310.pdfIn PDF document text
    • https://www.ppmcare.co.uk/wp-content/plugins/super-forms/uploads/php/files/13amvt5iotnl3sun48v3jjqheo/88064714062.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab32d997368---20402032169.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/mowibekal.pdfIn PDF document text
    • http://ahchala.com/img/file/jelajirojuvikurowirute.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a9aba35eb64---revafejokosanuxojifos.pdfIn PDF document text
    • https://bangprice.combangprice.com/beta/cms_image/file/miverujufaxesegonezaze.pdfIn PDF document text
    • http://sdds.be/userfiles/file/fewije.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/160840a8ed40e7---texuxikitofu.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_off0000becc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBECC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d6e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6E3 10832 bytes
SHA-256: 30b1c6bc0e40de3287d07e9ea6fae9590fa1bb86ab3768016687ceea72f1d1ca
font_02_sfnt_off0000efde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDE 17264 bytes
SHA-256: bf16ae16bb3fc0a170541ba73b8270be04bf0469a874810b3cc847d5b9534560