Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc7f6e56e6dfd8e0…

MALICIOUS

PDF

79.1 KB Created: 2021-09-13 07:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 7172e1c2de80755a88618c700676ea54 SHA-1: 4200aca7fcf8e04b4793f20380b0a2f169890e09 SHA-256: bc7f6e56e6dfd8e0f6042a2247e890fc5313fca0f8cf48e39039de9df6a6e5b7
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to other PDF files hosted on compromised websites. Heuristics indicate these are likely part of a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/0d1201b5486e5a3ec762c44f6f72dad9/38481337018.pdf In PDF document text
    • http://s13cf5ef.alojamientovirtual.com/ropadefutbolbarata/userfiles/file/69103676700.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/sidewel.pdfIn PDF document text
    • http://sportservistocik.cz/UserFiles/File/difividelikaf.pdfIn PDF document text
    • http://biplano.eu/userfiles/files/mepozamuzonolenarelololiv.pdfIn PDF document text
    • http://savemaxint.com/files/file/83290534945.pdfIn PDF document text
    • http://lpxs168.com/filespath/files/20210901161131.pdfIn PDF document text
    • http://medicalproduct.hu/images/files/sizisaludewixakuxivivi.pdfIn PDF document text
    • http://auksozvynas.lt/userfiles/file/76996338552.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210902_67A094FFD6CA91C3.pdfIn PDF document text
    • http://ctm.it/userfiles/file/vebenelinojujisetojafiga.pdfIn PDF document text
    • https://latrinquette.com/upload/editor/file/karur.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/23649919859.pdfIn PDF document text
    • https://sydneystudytour.com/accounting/userfiles/file/lusotuzolulolotebuxenuzok.pdfIn PDF document text
    • https://cristalensi.com/public/File/gugamaj.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16135808f6eb85---92678063259.pdfIn PDF document text
    • http://wanyuantemple.tw/userfiles/file/perudujeduzu.pdfIn PDF document text
    • http://mq-water.net/upload/kazuwakofukimobexejevenas.pdfIn PDF document text
    • http://mebizstekla.ru/userfiles/file/tususapuvuzafitinirob.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133cf74b99f1---24558164331.pdfIn PDF document text
    • https://viboot.traigiongthuha.com/ckfinder/userfiles/files/90799116497.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/j79fddk913ffue228fgp56e2l0/fozenez.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=unable+to+delete+some+documents+androidPDF 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_off0000cfe5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFE5 17984 bytes
SHA-256: e023b2e154943edeb2ae0abc1de91b8da02a154679117940cc4798a3dd4919be
font_01_sfnt_off0000fe11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE11 10776 bytes
SHA-256: 723bc2b3744898128d01255ffb1dca0ffbf19510bcf0cf1baeb6efd533a08564
font_02_sfnt_off000116d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1