Malicious PDF — malware analysis report

Static analysis result for SHA-256 631ad05129edc88b…

MALICIOUS

PDF

100.0 KB Created: 2021-09-03 02:48:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: eafdfcc39607ec9d3cfb9f76aa394608 SHA-1: 61850bf885c9920b884c30ad8d00ffd1a2b21aa8 SHA-256: 631ad05129edc88b705cfaf0cae8ced4cb55fa98501f20f6c166fb327e794bb0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest a phishing or malware distribution intent. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fedirer.pdf In PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608bf23e68d69---bigaleluzirigezam.pdfIn PDF document text
    • http://ros.by/ckfinder/userfiles/files/52121537167.pdfIn PDF document text
    • http://cjmjwarrickhudsonfamilyreunion.com/clients/9/9b/9be434dcd9982d5451de1b36a82eb828/File/87878572236.pdfIn PDF document text
    • http://lindendirect.com/ckfinder/userfiles/files/vesigogigor.pdfIn PDF document text
    • https://daleplumbinginc.com/wp-content/plugins/super-forms/uploads/php/files/1c972cd199d0e36334fc76f906403b06/napunu.pdfIn PDF document text
    • https://www.federatedlighting.com/wp-content/plugins/super-forms/uploads/php/files/4278c459533298a8ba792476b75377b2/bebun.pdfIn PDF document text
    • http://malbreil.com/userfiles/file/86751261634.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d0f5662ded---sovofubiso.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/wokojupulamuti.pdfIn PDF document text
    • https://moto-trend.cz/public/files/fck/file/reret.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/e240929b18e52ea9df61191df5f12e94/lodupopewubosire.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//51743912651.pdfIn PDF document text
    • https://siriusdynamics.com/assets/uploads/files/36560413107.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4bb1db73f1---36200966001.pdfIn PDF document text
    • http://pogservice.ru/userfiles/file/wapivoxibuja.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/gevevuwo.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16110af3c185a7---sonomulolaramajimifuvugi.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/4fbd310f974fdb0388522a020c1c4e4b/17582607479.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/zejajukit.pdfIn PDF document text
    • http://ministerium.pt/files/tanujumi.pdfIn PDF document text
    • http://quanhoangtsi.com/upload/quangtri/files/58313454884.pdfIn PDF document text
    • http://labonscafe.com/userfiles/81343954229.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608f945a79f89---78079573742.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=reliance+generator+transfer+switch+manualPDF 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_off00011c70.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C70 19932 bytes
SHA-256: 72e0905ab041c02ccafa2006703cadd4ca65335703fb2d3b2a92042fe7f70afa
font_01_sfnt_off000150d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x150D2 11012 bytes
SHA-256: dc25f4a998ffc9c1ecc161edd8bec1c7e4300a2791927ed1fb4f390060786f63
font_02_sfnt_off00016a51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16A51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1