Malicious PDF — malware analysis report

Static analysis result for SHA-256 4af338ed04236473…

MALICIOUS

PDF

157.2 KB Created: 2021-08-25 03:26:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3641185ab0d0f24ecd6f8105067ea376 SHA-1: 2a589389aaa1d53c9674e82fc44c4fb1caf92e17 SHA-256: 4af338ed0423647387d3843d401d49c82d8d4e217f0f068f604fa545b5f98a85
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and disposable domains, likely intended to host phishing pages or malware. The PDF structure itself is heavily obfuscated, and the document body is unreadable, suggesting it's designed to evade static analysis and deliver malicious content through its embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://mosoptagro.ru/wp-content/plugins/super-forms/uploads/php/files/65d1fd00d116ac1dcd77ce33964b9a66/99711751119.pdf In PDF document text
    • http://agataklimowska.pl/userfiles/file/38106063954.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/2ohdvtf5955t0u740ls4detss2/kupimaxin.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/d8124eeca194f232dc2e157760836392/wipigip.pdfIn PDF document text
    • https://stpeterscbs.ca/ckfinder/userfiles/files/jaruvumusanezeje.pdfIn PDF document text
    • http://0851gay.org/userfiles/202106file/2021062607040670554.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608421858ee10---1149635403.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/36131721461.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/hvavk4l7ct3crv99gehri9ernn/xazotizikolulowesizamapa.pdfIn PDF document text
    • https://olterus.com/contents//files/64081840473.pdfIn PDF document text
    • http://xn--h1aaebajlcgx.xn--p1ai/sadm_files/84557095622.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/belibi.pdfIn PDF document text
    • http://eviljoy.com/UserFiles/File/61097078692.pdfIn PDF document text
    • http://maraulsan.com/ckfinder/userfiles/files/makevuj.pdfIn PDF document text
    • https://lesfeesdelhetre.fr/upload/files/24138935356.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c78864404c6---nusuxisedanelifezebaso.pdfIn PDF document text
    • https://landbar.com/upload/files/48917590197.pdfIn PDF document text
    • https://larrialdiak.es/files/galeria/files/90433120520.pdfIn PDF document text
    • http://wypelnienia.kratex.pl/wp-content/plugins/super-forms/uploads/php/files/adb738af97bbc8cae1828c3cf965efe1/manujavetopezazijemufuwof.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c87097500c4---juzirozesonuv.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/kipodomulakifegof.pdfIn PDF document text
    • http://podlahypilat.cz/admin/file/20908754054.pdfIn PDF document text
    • http://hamdard.com/hamdard/app/webroot/img/ckfinder/userfiles/files/dekogu.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a9f20c4adc5---41542058189.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/lovatujite.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=biomaterials+in+ophthalmologyPDF 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_off000203bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x203BB 18052 bytes
SHA-256: c82624498a994a9424bff53f4d743975de768f7fdb48dc612d9b22d97cad5c11
font_01_sfnt_off000233ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x233CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00024be1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x24BE1 10864 bytes
SHA-256: 6009e5b8140f5482a53a5f8b2849380a7f3a006752abc3919a4d1872df1a662b