Malicious PDF — malware analysis report

Static analysis result for SHA-256 f766c55116207c8f…

MALICIOUS

PDF

85.3 KB Created: 2021-08-21 06:44:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 59d68d5381f6af671f6317e68dda4a8a SHA-1: d391d245cdbd12e5e8f3817c21313d2cfc0980c5 SHA-256: f766c55116207c8fdb5c6b3d88c9b11f54ac3c7d5957b02cccb265f8f99a46d0
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites and disposable domains, indicating a link farm designed to distribute malicious content or phish users. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classifiers also flagged it as malicious. The presence of multiple distinct hosts and the use of UTM parameters suggest an attempt to obscure the true destination and track campaign effectiveness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://cructi.ru/uplcv?utm_term=el+dador+de+recuerdos+resumen+por+cap%C3%ADtulos PDF link annotation
    • https://arnetbilgisayar.com/upload/ckfinder/files/20952346978.pdfIn PDF document text
    • http://gilleyfamilyreunion.com/clients/6/6c/6ce887ac6ce8bbcacf46524318b1f362/File/munuxusuxuxatusaki.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbcc190c83e---99362697366.pdfIn PDF document text
    • http://prattsofdouds.com/clients/d/d8/d85aab9f4bcbae69c8358f7a9990a0b1/File/pavitezolitafozigit.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/20622750015.pdfIn PDF document text
    • http://goang-hann.com/uploads/files/202108210407284896.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/fbbc6bc304e128251a32a7184cd9a140/2839334954.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1607c930f0088a---kemafegifudegodanoki.pdfIn PDF document text
    • http://www.mywil.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16092e5907b44f---17311467079.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/cced598affb6b69bd0094fc45c48fde7/46004907447.pdfIn PDF document text
    • http://altinay-law.com/images/file/56828736641.pdfIn PDF document text
    • http://pospatrans.cz/UserFiles/File/gibiposikarusiw.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/818dc734607d84d74129e21da1c838b4/98494334701.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/e1ov8pamqd7295stuu052cf2i2/14329504612.pdfIn PDF document text
    • https://www.psalighting.com/wp-content/plugins/super-forms/uploads/php/files/e74209ead1399fb65291de47d9c75f43/87639544565.pdfIn PDF document text
    • http://dwhs79.com/clients/15834/File/batopal.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/8655bbbead0ae9ce9d524f2b6443cfd3/wiwutup.pdfIn PDF document text
    • http://mhfmjournal.com/data/22/2/55/64/2544879/user/2788947/htdocs/userfiles/file/dunimodusomafaxoledusagos.pdfIn PDF document text
    • https://xistenze.com/files/files/kupulupirab.pdfIn PDF document text
    • https://malashealthcare.com/userfiles/files/44289337827.pdfIn PDF document text
    • http://christopherspubandgrille.com/userfiles/files/64133822132.pdfIn PDF document text
    • http://a-xian-coat.com/uploads//files/202107311229536821.pdfIn PDF document text
    • https://inclinedigital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160767f15500fe---63520830105.pdfIn PDF document text
    • https://olympicwroclaw.pl/zdjecia/fck/file/97254986542.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_off0000e5aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AA 10728 bytes
SHA-256: 85352354772a36d353135171af682c6b495b4eef58fe282f5448026f13e5764c
font_01_sfnt_off0000fe3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011650.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11650 17956 bytes
SHA-256: fe876ba20149ccf842a5ad7419a1d644b822225322fe2ea0061c5aeb06846b26