Malicious PDF — malware analysis report

Static analysis result for SHA-256 83df74fd495ab59f…

MALICIOUS

PDF

72.7 KB Created: 2021-09-25 13:08:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 128484b7692560ddd7ebfe099777e1b9 SHA-1: 943b801e197bca94e98b8fef9de38d7570b9c573 SHA-256: 83df74fd495ab59f1360e1bcb351081402aa24659a25b7c54531c4598e70ea50
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://glaze-metalart.com/upload/files/rasujanulemurolusopukov.pdf In PDF document text
    • http://tandprotheses.com/ckfinder/userfiles/files/349892946.pdfIn PDF document text
    • http://acm-medicali.it/userfiles/files/limudijewedasi.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ad9569482---56553824856.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/42408435545.pdfIn PDF document text
    • https://tsolisp.com/files/file/17414849229.pdfIn PDF document text
    • http://j1ent.com/userfiles/file/20210920123555.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/2210589547.pdfIn PDF document text
    • http://bigyikesmedia.com/home/xtremweb/public_html/consultinstitute/web/upload/files/7218305339.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/zegudopewegawaf.pdfIn PDF document text
    • http://aydinservis.com/ckfinder/userfiles/files/19151759265.pdfIn PDF document text
    • http://sin-hua.org/userfiles/73607406348.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/rowexixeni.pdfIn PDF document text
    • http://northcity.rs/slike/files/39155981738.pdfIn PDF document text
    • http://gestioniarmatoriali.it/37880741917.pdfIn PDF document text
    • http://computergramm.com/userfiles/file/zutog.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/files/nukexogimujup.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/87a399a90a45dfb6674d257681bbd051/83758114845.pdfIn PDF document text
    • http://mosvag.ru/img/lib/file/lanivarojum.pdfIn PDF document text
    • https://kiemtoandongnghi.com/public/plugins/ckfinder/userfiles/files/lapolawufasaduzegupu.pdfIn PDF document text
    • http://avstralianature.ru/ckfinder/userfiles/files/wofovetux.pdfIn PDF document text
    • http://ciarajewellery.com/editor_upload/file/vipojikizemokibedenimezon.pdfIn PDF document text
    • http://moderncarrent.com/user_img/files/6074911338.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/16145d5d2daa46---60673786113.pdfIn PDF document text
    • http://gzwep.com/img/file/2021911202359.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=video+star+mod+apkPDF 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_off0000b67b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB67B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ce8d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE8D 18352 bytes
SHA-256: 3b27e09700354c25a97dce5b3a1ff276107e620862a22bedf0c303249c6925a9
font_02_sfnt_off0000fd4e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD4E 10464 bytes
SHA-256: 4ce96994425fd360d0e84338819687fd68f9420252d82276ea5bdc353febd802