Malicious PDF — malware analysis report

Static analysis result for SHA-256 345212b3ef498498…

MALICIOUS

PDF

92.3 KB Created: 2021-10-25 20:06:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 4558d2590ae1c9a73d2477afc03da992 SHA-1: 780fb70a7c041c4538df5ef753576b63a46e9c3f SHA-256: 345212b3ef49849880371dfe2564cc2044f5fad3189938ae94bacb6a6430e6bd
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to a link farm hosted on disposable domains, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://szalkasszorutacskok.hu/app/webroot/files/content/files/xazawofiludigibewodasi.pdf In PDF document text
    • http://ydchem.cn/filespath/files/20210908201823.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/jidobode.pdfIn PDF document text
    • http://ks-klinika.ru/ckfinder/userfiles/files/18656725505.pdfIn PDF document text
    • http://abw10thstreetne.com/uploads/files/54697974884.pdfIn PDF document text
    • https://hophamthaibinh.com/upload/files/82504356890.pdfIn PDF document text
    • http://fluitec.fr/ressource/site-image/files/jijunijajurawobujokure.pdfIn PDF document text
    • https://2b3la571ga-70p.com/contents/files/legejijiviromamimativumaj.pdfIn PDF document text
    • http://stroykap.com/application/views/stroykap/userfiles/file/56081219502.pdfIn PDF document text
    • https://siangyun.com/upfiles/editor/files/viwojusizojesogalipasape.pdfIn PDF document text
    • https://www.playitdirect.ca/ckfinder/uploadfiles/files/92821966101.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/87570518009.pdfIn PDF document text
    • https://stiff.pl/ckfinder/userfiles/files/69826284692.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/namepixudukofujegisabofuk.pdfIn PDF document text
    • https://www.bbmnetlicitacoes.com.br/cms/ckfinder/upload/files/ladijedazeruxebasosoj.pdfIn PDF document text
    • http://ingpiazza.eu/userfiles/files/fupolitezagi.pdfIn PDF document text
    • http://catherine-massage.com/ckfinder/userfiles/files/76244181347.pdfIn PDF document text
    • http://araratmebel.ru/img/file/45041467093.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/70041919549.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/72555955013.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/161442d5582ca3---putilulilumupegenuganikuz.pdfIn PDF document text
    • http://brenderup.ro/mm/file/21106514557.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20211018020514.pdfIn PDF document text
    • http://yummyschool.com/_UploadFile/Images/file/26773666601.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/5bhJmFgkeCE/uplcv?utm_term=airpods+pro+check+serialPDF 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_off000102ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102EC 10480 bytes
SHA-256: 6550a9955b68b6def5f29a1b4866403e479b139cd603938a0959c8f82922a771
font_01_sfnt_off00011adc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11ADC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000132ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132EE 18444 bytes
SHA-256: 92ddce304e23cbe2226d7de8c3c346596d17062b6886b3fd8cbfd32abf03ecf5