Malicious PDF — malware analysis report

Static analysis result for SHA-256 376a7d2880ec9e78…

MALICIOUS

PDF

75.5 KB Created: 2021-09-15 01:42:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 49a8c8945ac4fe0adb71522ba4a7fd64 SHA-1: 8ad3d92e90d837a130af2bebdb0ff76ca0d625af SHA-256: 376a7d2880ec9e788ce3153681763b04c8e57e0eee31a5af1a88fc1ea166af44
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' indicates a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://luatsubienhoa.com/upload/ck/files/kesokezukotolapobesasuto.pdf In PDF document text
    • http://bnblspecialities.com/userfiles/files/42286499752.pdfIn PDF document text
    • http://elektro-galerie-hamburg.de/userfiles/file/tenoxu.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/sinoruvanidawazerefeweru.pdfIn PDF document text
    • http://etabetasurvey.com/userfiles/files/30466860838.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd4f7a7f3e---lamazaxiwabisa.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/powesada.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/80343281444.pdfIn PDF document text
    • https://klcconsulting.eu/klc/file/25106210342.pdfIn PDF document text
    • http://podlahyadvere.sk/editor_uploads/system/files/24774964702.pdfIn PDF document text
    • http://saraya-shop.ru/upload/files/zinekovege.pdfIn PDF document text
    • http://krishikhabar.net/assets/ckfinder/core/connector/php/uploads/files/gejisixabupefadomef.pdfIn PDF document text
    • https://rockeit.com/userfiles/file/pixafirewalesuxugodi.pdfIn PDF document text
    • http://gibisch.com/files/files/xalegatexe.pdfIn PDF document text
    • https://wemservice.com/ckfinder/userfiles/files/nagejalujojomulevuwududo.pdfIn PDF document text
    • http://avalon-essenzen.at/userfiles/file/25527527360.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb50579204---75366939877.pdfIn PDF document text
    • http://trungtamsangloc.vn/uploads/ck_upload/files/nogemam.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/ae8ea76b5f782906ee436fb972f05e1e/gowigifixakunexif.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/c97a4490aa96f542417a700c8c0f3a66/forafunos.pdfIn PDF document text
    • http://jlm-kg.com/uploads/file/36091941499.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/202197718258023.pdfIn PDF document text
    • http://autoscuolepintozzi.it/userfiles/files/78262742934.pdfIn PDF document text
    • http://www.macrolepidoptera.hu/userfiles/files/fesobobijigojuxewij.pdfIn PDF document text
    • https://prolocolidodisavio.org/ckfinder/userfiles/files/tekijogezutok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=dragon+ball+idle+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_off0000c356.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC356 10704 bytes
SHA-256: 004094336d12c63fd46e90e59016d1336f1f81dbe6305543e9a410a07a69a73b
font_01_sfnt_off0000db50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB50 17252 bytes
SHA-256: 956ff937b5a4ac211452c496be6fd1ae4cd94921733bb3ee5e2fb201ed51ad39
font_02_sfnt_off00010815.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10815 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1