Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf445143f630bcde…

MALICIOUS

PDF

73.4 KB Created: 2021-09-25 02:57:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1858ec21dcf07d22f19d3d214857c675 SHA-1: 6a170034c454dcc8f20abfcb8759038c3cef9634 SHA-256: cf445143f630bcdeb203cb4c0e297d454fe0b8abc34cd2a0cc56fb61b5edf30f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the PDF structure itself is used to host and distribute these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://archism.ru/uplcv?utm_term=can+apps+go+on+sd+card PDF link annotation
    • http://balatonfurediallatorvos.hu/userfiles/file/59903108500.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c382dd58a6---xerurukovu.pdfIn PDF document text
    • https://lamaisonducoeur.ca/upload/editor/file/ginekekurava.pdfIn PDF document text
    • http://julianina.de/upload/file/25180492249.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///wizakiwasi.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/nikufixulufusorasi.pdfIn PDF document text
    • http://hnfhdc.com/UpLoadFile/2021090917314928265.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16143b2dede81f---mosijede.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/85344320527.pdfIn PDF document text
    • http://hysansam.com/fckeditor/userfiles/image/xeloxejemezorigupajumogu.pdfIn PDF document text
    • https://sukaunited4d.vip/contents/files/96268467161.pdfIn PDF document text
    • https://heyratacademy.ir/file/71965107467.pdfIn PDF document text
    • https://globaldreamindia.com/webcms/file/dulojun.pdfIn PDF document text
    • http://pegasomeeting.medcoast.net/ckfinder/userfiles/files/limamotowujesagi.pdfIn PDF document text
    • http://eortak.com/img/fck_temp/file/25029949635.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/6ca9iqbd88t606kpu8ji05mdf6/daxukugotakuxame.pdfIn PDF document text
    • http://heaig.org/editor/ckfinder/userfiles/files/78336481180.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138925de2530---femewufevara.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/7585007177.pdfIn PDF document text
    • https://csam-villepinte.org/uploads/images/file/pejujitod.pdfIn PDF document text
    • http://houselandia.ru/files/5944102010.pdfIn PDF document text
    • https://akvaguru.hu/user/file/febiguvukujuniwiv.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/73405883249.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-9-24/20210924125837870475.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_off0000bad0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAD0 18032 bytes
SHA-256: 90538c0972a0bba60d7c15ea4abe5575ae62dffb14f9e95bd73619d1a987dcd5
font_01_sfnt_off0000e8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EF 10352 bytes
SHA-256: b0a17ef42b1460f7c3c380bed09916e4848146cca8793e0e59d6060ff631478d