Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d4c570108549db0…

MALICIOUS

PDF

83.8 KB Created: 2021-06-28 16:50:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 05f0cdcef7f02f13ed63e11a205bcc4b SHA-1: d696cd1a4a0feb22aac680e61af39c843f70d6f8 SHA-256: 8d4c570108549db08c483baa7f61f2a1ad1f26e6456575c48205ec7026e795fe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites, suggesting a link farm designed to distribute malware or facilitate phishing. The presence of external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic further support this attack pattern. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://voyagerf.ru/wp-content/plugins/super-forms/uploads/php/files/05f3025040ffa00fdce58dd4047d1b6d/57310323790.pdf In PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/lojq22rv63makt24pum22sud8j/wagufifepizeni.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee13b4d7ee---javepilidavesebuni.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/76587890644.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbe46f195b8---fabozoragofo.pdfIn PDF document text
    • https://cuisinescartier.ca/upload/editor/file/fejutipatid.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a75621071ce---nilaz.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/mekha2b2923sq63q7a8sctb2sq/40296275438.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/nonolifosobizepis.pdfIn PDF document text
    • http://rszm88.com/upfolder/e/files/20210628164624.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d77c2f167de---47637855886.pdfIn PDF document text
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/8c6d5d6e77a4ed8abf020a27d2bb13e9/37456301010.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608fb59c6d220---luvumonilafawugesuti.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a85f880c688---38516422336.pdfIn PDF document text
    • http://webursitet.org/Files/file/totuxar.pdfIn PDF document text
    • https://asi-filter.pl/files/file/damipimel.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4d8c725be7---vupupobutaledexowosijev.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/40651063795.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abf5609111c---44339920202.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ef125ddecc---62524088860.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/f8a6eeb5c1d192ed9d9f7a4ab7f9b6c7/fijasajilituwobebe.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/79940695542.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/4da9ab1dae087e3172b1509c61497b63/lurowujod.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/54e1bcf23b691c065c2740e7b6354683/tejuvatipusenuzob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=pacemaker+operation+costPDF 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_off0000e64c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE64C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE5E 16764 bytes
SHA-256: 6b0504a3b79e5204c778a6daf5577e2af3d8db777c8a557e768f5eac511617d9
font_02_sfnt_off00012a20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A20 10580 bytes
SHA-256: bb750cb1b9c60a6f483673953963cbdc4e69a20b4c53010ed7fff5ddd376670e