Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b9925d8c78e76a4…

MALICIOUS

PDF

92.3 KB Created: 2021-07-13 17:01:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: a4e3d94359fc479499decb822acc7182 SHA-1: 4b08b428e0e12c7b6643c066f190ee81bd0832ea SHA-256: 6b9925d8c78e76a46ee87fd02cebd36e88887df3b2765e793d68cdbd6f86f817
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. It contains numerous embedded URLs that form a link farm, with several pointing to compromised CMS upload directories. The ML classifier also strongly indicated maliciousness. The primary attack pattern involves directing users to external sites via these links, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://ckrestaurantgroup.com/ckfinder/userfiles/files/15654373184.pdf In PDF document text
    • https://golf-tout-terrain.com/publish/page/file/pajagekoxuxavuzabadunota.pdfIn PDF document text
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/lq38kgv2de6dpr8knsvl77kt96/56556141180.pdfIn PDF document text
    • http://haohanlegend.com/Uploadfiles/files/90512802337.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/ibrhuco333c7hu1dp050uuvdtf/63732309601.pdfIn PDF document text
    • http://hillcountryawningsandsunscreens.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072bc4966f9e---voxusodufugaluniva.pdfIn PDF document text
    • http://madison62alumni.com/clients/e/e8/e84cd6a5166dbe8c5f6852bff763f4b2/File/62638123950.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/gilawul.pdfIn PDF document text
    • http://varanini.pl/userfiles/file/50665443969.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/lilixirivapobuwiw.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c93efc033c---xetevagixedukinemidu.pdfIn PDF document text
    • http://kondicionery-ivanteevka.ru/upload_picture/file/43231893933.pdfIn PDF document text
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/60689113933.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/21164251356.pdfIn PDF document text
    • http://greenlivinggarden.com/htdocs/UserFiles/file/42265952647.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/6b61651508ab0df09d870d3299762b61/fezekamisidibetupufenajel.pdfIn PDF document text
    • http://ajarnveerapong.com/UserFiles/file/29255346883.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609da42063e9a---44913043949.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098b2048a5c1---jogadifupevefidalawifuxa.pdfIn PDF document text
    • https://regeneracion-capilar.com/wp-content/plugins/super-forms/uploads/php/files/8c785c4af345ba239cd61662a216a881/81333957520.pdfIn PDF document text
    • https://berbagiangka.com/contents//files/2810329564.pdfIn PDF document text
    • http://smflow.in/admin/uploads/file/kuzubika.pdfIn PDF document text
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/b0qlrr7a5dop5al6el4igepp2p/lagixenivuwipit.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160762f1812b95---pikise.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=customer+satisfaction+in+telecommunication+industry+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_off0001016f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1016F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011981.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11981 20096 bytes
SHA-256: 074e228f4cef84926bedf65a878ee719f981e2fc50cd1693e980b59ec6328054
font_02_sfnt_off000149b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149B5 11024 bytes
SHA-256: 2120b130f32edb995d483d6038484f0519b94b29a0bcda266d266d92ef340bff