Malicious PDF — malware analysis report

Static analysis result for SHA-256 21c3ab8a50ddf81a…

MALICIOUS

PDF

102.2 KB Created: 2021-07-04 22:52:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 31718ad0823792060972423c86791466 SHA-1: 6bb08da5fa504182a0fa94532bf1263529ff0a6d SHA-256: 21c3ab8a50ddf81a9fee4988b013387020fe06577ac671d7099e935ec222e7d5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, forming a link farm. The primary function appears to be redirecting users to malicious content, likely for phishing or malware delivery, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3d04f422d5---gexunokifisililiviguro.pdf In PDF document text
    • http://sdds.be/userfiles/file/19117807262.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/t1enta6bgfiiq4j8opan3kctj5/73388721281.pdfIn PDF document text
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16073535faa1f2---kanidi.pdfIn PDF document text
    • http://janatalnajaf.com/basefile/janatalnajafcom/files/67914479103.pdfIn PDF document text
    • https://carparts-fixture.com/file/file/47624877579.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/7du35mks5vu90eb20a0a0qj9lp/87372607687.pdfIn PDF document text
    • https://cottonweb.net/userfiles/file/18767541930.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/a80r8011lch2r6qrs1kontg8qh/87360253533.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab51664fd06---56873445738.pdfIn PDF document text
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/2794b232351f1b6243e7f770ac894d0c/84700955032.pdfIn PDF document text
    • https://directorvincentchow.com/fck_filemanager_upload/file/52661069721.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608410c745d82---8828597694.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/11bedj8550kiru77rkol86gv44/runupemoxenilenag.pdfIn PDF document text
    • http://group-anons.ru/userfiles/files/lesawuwakeseruma.pdfIn PDF document text
    • http://host.keraladreamhomes.com/~viswabrahmathach/admin/fckeditor/editor/filemanager/connectors/php/userfiles/file/kupabexutuzifexukizi.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/70c7429f1c58a109a72fbe0180a655d5/85237122850.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/zevosubajalumepodulux.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/b75dbcc9c07dc6e41bffdc628771db53/nigeferuvogadav.pdfIn PDF document text
    • http://iraneto.com/basefile/iranetocom/files/nadozemiviri.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/38915182203.pdfIn PDF document text
    • http://sobsai.com/ckfinder/userfiles/files/detir.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/rekegupibin.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/r6smqdbtkh03fe4vlog0p5c3na/9851411260.pdfIn PDF document text
    • http://isvpro.com/custom/files/22647904068.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=innate+immunity+first+and+second+line+of+defensePDF 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_off00012d0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001451f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1451F 17228 bytes
SHA-256: 1e5fa0df9bab4405a3e998f8e899e4e9fe92631dcd11baf7dd153427dad4e9c1
font_02_sfnt_off00017255.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17255 10804 bytes
SHA-256: 95aa9267ea5446bf17bfe05bf4af4224e117958defb9e282db0b3019bb7adcec