Malicious PDF — malware analysis report

Static analysis result for SHA-256 c2491db4f962edd9…

MALICIOUS

PDF

80.9 KB Created: 2021-09-09 10:29:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: b10d63e1a0e35380817261dc7246e456 SHA-1: 5e0a9e60709882483583de928e26738ff0df3af9 SHA-256: c2491db4f962edd929f46778b014064c279f6512d62f15c072b371e472a6206e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://oniceh.ru/uplcv?utm_term=desi+serna+fretboard+theory+pdf PDF link annotation
    • http://yuanda-boiler.com/d/files/20629179973.pdfIn PDF document text
    • http://winso.tw/userfiles/file/89561630117.pdfIn PDF document text
    • https://derya.afmiletisimajansi.info/resimler/files/25266103267.pdfIn PDF document text
    • http://skipjackpoke.com/ckfinder/userfiles/files/63126158101.pdfIn PDF document text
    • https://bonaparte.cappencms.com/templates/files/birawekevep.pdfIn PDF document text
    • http://cbstav.cz/file/diwewuxatobavufabirukos.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/35031705993.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/31680100280.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613575dfecdc4---winikew.pdfIn PDF document text
    • https://strategie-forex.com/ckfinder/userfiles/files/gaxirikumatezetejagibow.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///202109025852_967840961.pdfIn PDF document text
    • https://licorne-hotel-restaurant.com/userfiles/file/69361326037.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/10462892771.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109060623108459.pdfIn PDF document text
    • http://projecthouse.bg/uploads/CKfinder/files/jogazogipeki.pdfIn PDF document text
    • https://paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/78947940696.pdfIn PDF document text
    • https://vinocastillo.hu/editor_up/78016800793.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/63413004117.pdfIn PDF document text
    • https://idroilektriki.gr/files/file/2762470868.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16130f8d0ee780---sajojasixunanutoledekape.pdfIn PDF document text
    • http://babyshelter.net/assets/upload/files/91484780430.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133fe49457af---gojemabap.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/sukulubuxamumirofivi.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/41697643862.pdfIn PDF document text
    • http://wwsm-hk.com/files/file/wakazowodexurozupufe.pdfIn PDF document text
    • https://hotelcorona.ro/files/70661930999.pdfIn PDF document text
    • https://sofanet.ro/ckfinder/userfiles/files/fejagomelurabeseja.pdfIn PDF document text
    • http://novichiha.ru/pic/file/nabojolijorusagisiket.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_off0000da2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f241.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF241 10804 bytes
SHA-256: 7092bc9720cd4d6c13f45024f81b2ff486909696ddda901dc356f62ba57703e5
font_02_sfnt_off00010aec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AEC 16572 bytes
SHA-256: b3dad0b04ca1b288e7b86ec71d675413158fde5f0b5217be18dee61264e72f91