Malicious PDF — malware analysis report

Static analysis result for SHA-256 827b1d0358cc96bf…

MALICIOUS

PDF

82.5 KB Created: 2021-09-22 20:28:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3d2d221762eea81fb0363371e9f540b3 SHA-1: 35746589781f2cfcb3ef90da62945f5794e61de7 SHA-256: 827b1d0358cc96bf2567ce39a485fa53a616e73f168c571f52e32ee85877a817
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting it functions as a link farm. The presence of 'utm_term' parameters in some URLs indicates a potential phishing or traffic redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://chcial.ru/uplcv?utm_term=play+store+black+icon PDF link annotation
    • https://linkevicius.com/upload/galery/file/17608173405.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614a1b1541785---5236486249.pdfIn PDF document text
    • http://baovekhucongnghiep.com/upload/files/vatiwag.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/99894160226.pdfIn PDF document text
    • http://ct-tci.com/cttax/userfiles/files/podawebidapudazuvofobaxix.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613aca3a6c9c5---romixunumipisana.pdfIn PDF document text
    • https://vonia.mikludava.lt/images/files/ziwade.pdfIn PDF document text
    • http://tivatijapan.com/uploads/userfiles/file/50372492049.pdfIn PDF document text
    • http://businesslegalgroup.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tapotilijavuvogu.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/rupopogigibifajufaketus.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/19218998263.pdfIn PDF document text
    • http://omgmediatank.com/userfiles/files/51447427532.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/xixedogofotonafatiputuj.pdfIn PDF document text
    • https://www.uflo.edu.ar/ckfinder/archivos/documentos/rixifonufunoselogemaj.pdfIn PDF document text
    • https://ruja.lv/uploaded/file/tarinuwebirawika.pdfIn PDF document text
    • http://caigeshi.com/uploadfile/file/2021090304340473499.pdfIn PDF document text
    • https://giraffeng.net/infodaily/gen-ckfinder/userfiles/files/dezema.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/37487336872.pdfIn PDF document text
    • http://retroldn.com/userfiles/file/mirowelifi.pdfIn PDF document text
    • http://qazaqbanki.kz/data/content/files/vitadejolugituxoxatowi.pdfIn PDF document text
    • http://www.swaving-stalinrichting.nl/ckfinder/userfiles/files/36785720198.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/161371ac08539b---bixaf.pdfIn PDF document text
    • https://cfbadalona.net/ckdata/files/fanusuk.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/16145ce01621ac---sabosegufebev.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_off0000de76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE76 17704 bytes
SHA-256: 4ad8c1a8274bfdfa1b6fa8ff4364e9bac4998c956b6a44f68a2fd9bf521698d9
font_01_sfnt_off00010c2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C2E 10572 bytes
SHA-256: d9471633aa9fc6864ce8c47147d1daa9c9fff638776f91b442181d792c11d855
font_02_sfnt_off00012488.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12488 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1