Malicious PDF — malware analysis report

Static analysis result for SHA-256 4af56cac46ad10ff…

MALICIOUS

PDF

81.6 KB Created: 2021-09-21 09:24:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 634b6031ce06cad4ec677031cd765d48 SHA-1: 37949a934bf538477b86b90cbb4843a9d8000182 SHA-256: 4af56cac46ad10ff456fb45a12dff1fed4cfacf5624c6e81e2b6b950c25d92e8
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to compromised websites, suggesting a phishing or malware distribution scheme. The PDF structure and link farm heuristics further support its role as a lure to external, potentially malicious, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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=mammoth+book+of+chess+pdf PDF link annotation
    • http://kristiankutschera.de/userfiles/file/80157044021.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/83204507836.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/h6v9cftf4lum71a3rhre17d924/fejewamigowiwevinivajefun.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/wigipudowapejarovowosif.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614093c494368---67287131495.pdfIn PDF document text
    • http://a899.net/userfiles/file/98266668296.pdfIn PDF document text
    • https://cometsecurity.in/admin/userfiles/file/1393089146.pdfIn PDF document text
    • http://fese.in/ienupdimages/images/files/92589290681.pdfIn PDF document text
    • http://sportsbettingconsultants.net/cote_dor_import/admin/ckfinder/userfiles/files/57112363897.pdfIn PDF document text
    • http://mtcongnghiepxanh.com/upload/fckimagesfile/kevetepejubebulili.pdfIn PDF document text
    • https://holyfamilyhospitals.com/ckfinder/userfiles/files/lovomegowipubojasidekot.pdfIn PDF document text
    • http://okeefesreef.com/ckfinder/userfiles/files/lukonumulegibaj.pdfIn PDF document text
    • http://konstruktor33.ru/app/webroot/files/files/berisi.pdfIn PDF document text
    • http://premiercontractinginc.com/files/file/28388714901.pdfIn PDF document text
    • http://schokoladenfontaene.de/idata/xibuposexopakimaxekopi.pdfIn PDF document text
    • https://ags-car.com/upload/files/mejutenidami.pdfIn PDF document text
    • http://archetipoingegneria.it/userfiles/files/bilafufataki.pdfIn PDF document text
    • http://keitbg.com/images/files/titumuwifajesudeji.pdfIn PDF document text
    • https://thietbigas.net/media/files/kupukazofuzujine.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/tanonigu.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131b76da6c50---puvologivusofoniwasi.pdfIn PDF document text
    • http://6nergy.fr/6nergy/sites/default/user/file/5577432039.pdfIn PDF document text
    • http://pinxedien.net/upload/files/libuwujanezikowinudagom.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_off0000de18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f62f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62F 10768 bytes
SHA-256: 7a0651a85764485fe79c6761f3dafebae1d7140a74eccc5e238064f845db37ad
font_02_sfnt_off00010ed3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED3 16272 bytes
SHA-256: bf3414ea8591fe601add200f85b476beb0dc14bab9487bc95285f1b2b07ea51f