Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a91461115d96281…

MALICIOUS

PDF

74.2 KB Created: 2021-09-16 04:27:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cda19df9b14d300161a2ddef10f4fd0f SHA-1: c23f03d1af35bfc2ef66c028c5af079fec0d8f68 SHA-256: 7a91461115d962813aa7a13500fa15eb0792a82d894e7f16da626b78ce247f66
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to domains associated with link farms or compromised content management systems. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's structure and URL distribution suggest it's designed to lure users to external, potentially malicious, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://edisonprivateschoolbeta.com/cote_dor_import/admin/ckfinder/userfiles/files/47848019782.pdf In PDF document text
    • https://promobryansk.ru/userfiles/files/ditofepasemosudezubo.pdfIn PDF document text
    • https://lockerova.eu/admin/upload/documents/75706986587.pdfIn PDF document text
    • http://pastoret.it/userfiles/files/tojosufijafugufebebo.pdfIn PDF document text
    • http://amsaneeraus.fi/userfiles/files/nobikevitu.pdfIn PDF document text
    • http://blossomtour.net/FileData/ckfinder/files/20210909_32CFA01D9EA765D8.pdfIn PDF document text
    • https://diphong.com/uploads/30916623346.pdfIn PDF document text
    • https://www.sesc.com.ua/wp-content/plugins/super-forms/uploads/php/files/vm03fg0fuadekaho9l0j3d6tr2/21501433401.pdfIn PDF document text
    • http://xn--krmer-dnnebacke-1kb72b.de/files/file/94418702044.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1613c5a68551b7---31973051453.pdfIn PDF document text
    • http://trungnguyenjsc.vn/uploads/image/files/bavezokefejowixuwoxoses.pdfIn PDF document text
    • http://bhavalaya.org/ckfinder/userfiles/files/62748336328.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/1ee50eb2effe315688b7f67971814926/43304772105.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/gidabodezolelod.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f4e8ed74a1---9945611835.pdfIn PDF document text
    • https://mp2020.csysadmin.com/ckfinder/userfiles/files/92791141891.pdfIn PDF document text
    • http://coimbra.hu/uploads/ckfinder/userfiles/files/80490141302.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/15923378889.pdfIn PDF document text
    • https://www.rapn.ru/ckfinder/userfiles/files/sizofuvataputodejosezuju.pdfIn PDF document text
    • http://aorganboys.handyfriendship.com/upload/files/1065212101.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/23111924903.pdfIn PDF document text
    • http://www.globalnautique.nl/upload/files/gulidesatoxolidifulunov.pdfIn PDF document text
    • https://jotekonybakterium.hu/userfiles/files/4892242726.pdfIn PDF document text
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/zudezezuxeputuxilos.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/99675379936.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=light+browser+apkPDF 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_off0000bcb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCB9 10656 bytes
SHA-256: 396641e66983c5b4f764e1966e4c8251c0fb87aada49147a2bcaa44591527c83
font_01_sfnt_off0000d526.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD526 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED38 18068 bytes
SHA-256: 145797bfed292e152f6c0c79015768d2be185bf4056f317ec060cfd486ad63ac