Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c41a055f825a7dc…

MALICIOUS

PDF

82.1 KB Created: 2021-09-06 01:03:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: dda8261885db1adc29b6bb22c0b23e4b SHA-1: 47d8c502215b2e1c67d8f33d21ee047fd50b76bf SHA-256: 8c41a055f825a7dcad71b2f0606c36d34237ac3b2b582ec3110893cc9f72c909
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://cornerstonelaw.eu/userfiles//file/44712709784.pdf In PDF document text
    • http://cabini.it/userfiles/files/22386036247.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/rubagisidefivajiw.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/navubakokukavegabodixule.pdfIn PDF document text
    • http://ranagro.com/files/koxulugiv.pdfIn PDF document text
    • https://lwim-ouargla.dz/ar/files/banosujute.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/53f0820972f641f09f33a9738a37e8a5/ruderojozadofozanurub.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/16099d0988ccc8---78645274111.pdfIn PDF document text
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/a5bah85p8kjo69hvddi9rnbk5r/pasedomusi.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/b7657ff5d1d413a8b71e3e71b3173e43/jogetalaxitonuvewene.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160cbb42edd5c2---92193851176.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/16127f4275b113---nafokulalorinudonozo.pdfIn PDF document text
    • https://medtek.vn/storage/file/97363174078.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/60919156793.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/5f71c3a966d3f19609461d334cbbd4a6/wamifutuxubojawifuxanakit.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/14775651318.pdfIn PDF document text
    • http://barcelonasixtytwo.com/userfiles/file/widaxuwibevovixakabak.pdfIn PDF document text
    • http://planetamama.ru/files/file/46204441324.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/kupekogara.pdfIn PDF document text
    • http://ventmetal.ru/userfiles/files/zeterorovitibapekim.pdfIn PDF document text
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/ab8f19fa73f904d39ec2fd99bf818fa1/58578287914.pdfIn PDF document text
    • http://ave-france.com/pics/files/suzusuvugegejozedorobini.pdfIn PDF document text
    • http://sumbulefendiegitimvakfi.com/resimler/files/gafunuxel.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=esv+systematic+theology+study+bible+pdfPDF 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_off0000d97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD97D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f18f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18F 18396 bytes
SHA-256: aa25b9a85827a60ecb5adfcb736ccb29e7336dcb6398cbeb2cba8adf5525983a
font_02_sfnt_off000120c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120C5 11264 bytes
SHA-256: d169e96f051b4d551de95dcf1198d24230fcd8bf20af48d6729f4d2e3cddf42e