Malicious PDF — malware analysis report

Static analysis result for SHA-256 a740bc46f00b1232…

MALICIOUS

PDF

88.9 KB Created: 2021-06-26 01:09:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: dac4487a13838046277b6f7b080744b3 SHA-1: ad28c273108ec6a3d0115402d5bcde806c2b4c24 SHA-256: a740bc46f00b123272fa57700a31df990322260d61f413db001061222e8a51e5
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating it likely contains malicious content. It functions as a link farm, with numerous URLs pointing to external PDF files hosted on compromised or disposable domains. The presence of these links suggests an attempt to distribute further malicious content or engage in SEO manipulation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609e09c462dd8---78385546334.pdf In PDF document text
    • http://parkhigh65.com/clients/4970/File/gebivatuzuk.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/maradomizaxanivenemasin.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/4741206977.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/ed98d09643eeddc1e68936cb0517a254/bupimejadapilotusupex.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/e2c4b26d16c2a4b49e021a064ed3f422/92302986346.pdfIn PDF document text
    • https://cherrychile.cl/cherry/uploads/contenido/files/bedawuzidijorepixenawo.pdfIn PDF document text
    • https://grup-insaat.com/userfiles/file/2365707338.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090331385ea1---8470378713.pdfIn PDF document text
    • http://prodottoitalia.eu/userfiles/files/gobasemavofexov.pdfIn PDF document text
    • https://www.surajinformatics.com/wp-content/plugins/super-forms/uploads/php/files/7f5ec6732a8ef7db31dd364dfeb272db/72531271386.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160773cc04ca79---mipojipi.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce6ff2f7af---zevoro.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160927048600b5---85571208110.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/e0871f8ee380a458e18e1a61ec990c46/76956381240.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/16082e8ea0daff---karosoxuxin.pdfIn PDF document text
    • https://vnsteeldetailing.com/UserFiles/files/31680954785.pdfIn PDF document text
    • https://kodcomputers.ro/2664/uploads/47290483251.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b594dbed654---kaxevatolo.pdfIn PDF document text
    • https://aedwea.com/upload/foto/kanavafiregan.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608a27d86a79e---19963561352.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/1606d86e964c58---39174350407.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d1b07194b5e---8424961279.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/rodufedafodamomemoj.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf58020190---97022109356.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=earth+day+coloring+pages+for+adultsPDF link annotation
    • http://irodori.kir.jp/files/file/76577828877.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_off0000f65b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65B 16972 bytes
SHA-256: d384980bdb1a95e1fa8c5ce232c84cbabd4bb2dd62d64c0e2e035509ed6e5051
font_01_sfnt_off00012273.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12273 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013a8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A8A 11096 bytes
SHA-256: 6cca36625bc77dc89e6dd3aa5edaf2a3ea161383656023fcb829261d61419737