Malicious PDF — malware analysis report

Static analysis result for SHA-256 4682d6dfe4b64dd3…

MALICIOUS

PDF

81.8 KB Created: 2021-08-17 19:28:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: fe23385629c8edaf35d49c4f8d4b5e69 SHA-1: 415bd82cd93c705b448eb68cf263921919b3dee0 SHA-256: 4682d6dfe4b64dd3b51b14818f2e72c4db082e907a9c4e4168ffa403cf24f52d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external URIs and link farms, many hosted on compromised CMS uploads, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct content analysis, but the heuristics point to a link farm designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://nomylo.ru/uplcv?utm_term=examen+de+excel+avanzado+practico PDF link annotation
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104f5aa69b96---mojivotediridasilaxu.pdfIn PDF document text
    • http://supragyn.cz/userfiles/file/kujebijedap.pdfIn PDF document text
    • http://taikenplan.jp/ckfinder/userfiles/files/37952901585.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d681bae0afd---20112032676.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/roxodopeduzufopogawelufo.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ff5a32a6201---1586509940.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/tilozupatuzibenapob.pdfIn PDF document text
    • https://robertbah.si/files/file/84769975511.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/67239371577.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/639bd5faa03d5c416c85e63b082e0cc9/84814488988.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c37e36504ee---zogaramapinosofetidolemun.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/wufukapefekovoxezi.pdfIn PDF document text
    • https://morabia.fi/images/file/tomukusatilufogadol.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/573530618d939782aa478c869ef57764/41592497922.pdfIn PDF document text
    • https://ctsgroups.asia/images/file/89088956524.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c9d8d710a29---86102311550.pdfIn PDF document text
    • http://sskj.pl/userfiles/file/63572537628.pdfIn PDF document text
    • http://umiyawoodworks.com/fckdb/userfiles/file/22756267650.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/07e337835460ef93d973b05a06614539/87246265264.pdfIn PDF document text
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/030cd163202d517d58d01d626763d32e/kifuwag.pdfIn PDF document text
    • http://kursadowicz.pl/Upload/file/60989170351.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/d143136dd3b887fa163ddb9934ab6989/52820694105.pdfIn PDF document text
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/c50b73b28bbf9452e5aba51674ada660/73735173562.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/36008483204.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/99148865514.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_off0000da99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA99 17812 bytes
SHA-256: f8f221d481a5aa7967a205700252a755ebfa8bd6068ec7de4f8f2f555e7068c0
font_01_sfnt_off00010720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10720 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F37 10720 bytes
SHA-256: 759e89e73cf814f1dbd66f4fd6a4b3189234d837cb26f51626745b4b47299b98