Malicious PDF — malware analysis report

Static analysis result for SHA-256 c701af6f36fc10e0…

MALICIOUS

PDF

73.3 KB Created: 2021-09-18 18:54:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 785ac14864be7ea957e6ee2c8fd70024 SHA-1: a5d09a6080d893fc7b6441ae8c7f4fe87106e964 SHA-256: c701af6f36fc10e0dfc47905449afa2ec581a44341467a490931c46005b0a06b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

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://synerhu.ru/uplcv?utm_term=boxing+gym+story+free+download PDF link annotation
    • http://nfraccon.org/userfiles/file/wazesuvekazekajux.pdfIn PDF document text
    • http://innova-perila.ru/upload/files/felexowigujiretebo.pdfIn PDF document text
    • http://www.rify.us/cms-uploads/files/13662471689.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/bilufozuko.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f06b468882---69036703566.pdfIn PDF document text
    • https://actaviaserica.org/board/file/files/nuwedoboxovezib.pdfIn PDF document text
    • http://christ-china.com/filespath/files/20210902152452.pdfIn PDF document text
    • https://hoya.mobioptika.hr/UserFiles/file/doxizaneberenuvinuzawugux.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/c7460ac298bb370792c9f7ab861bc1c5/6964253702.pdfIn PDF document text
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/zigiraj.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/16019408147.pdfIn PDF document text
    • https://agrilaui.com/userfiles/file/55659355439.pdfIn PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/98946046101.pdfIn PDF document text
    • https://bi-kiesabbau.de/cmsimple/images/file/98156598463.pdfIn PDF document text
    • https://moderator.lt/components/com_mijoshop/opencart/image/data/files/matuwulilelenamekewexatig.pdfIn PDF document text
    • https://tempegaring.com/contents/files/jukavuteropopupogi.pdfIn PDF document text
    • https://www.xyoaa.org/sites/default/files/files/vegogitegobopolomutipure.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613456e68c0c9---vowutuwejumipenisib.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631106064.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/84180279561.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1613dd2f780188---34745978568.pdfIn PDF document text
    • http://jobsandhi.com/uploaded_files/userfiles/files/65861839937.pdfIn PDF document text
    • http://olynskiconstruction.com/pics/file/zezibasuvas.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c1aa580c10---36543633370.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_off0000bb28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB28 11052 bytes
SHA-256: 149b04f70929a0bfde785ca95196f0fb61c86d23742cea952a99d7bc8de78324
font_01_sfnt_off0000d4cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CD 16428 bytes
SHA-256: f011792cda7e3d62911dfbac328404c27cd32252e7e48231b38227d25b9dc495
font_02_sfnt_off0000fefa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEFA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1