Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51fef5bd117cf24…

MALICIOUS

PDF

92.3 KB Created: 2021-09-05 03:23:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0009e63297a6e92b9ddb83203748237c SHA-1: 18fc361cb5c8294dc8616053be89e7ccbbef24d7 SHA-256: a51fef5bd117cf24f959ddd3850a2f81a784620e67a0c4c069a786919d266829
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to unknown or compromised domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. The file's structure and the presence of multiple external URIs support the classification as a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://reitinguok.lt/userfiles/file/218660250.pdf In PDF document text
    • http://wadirumshootingstars.com/userfiles/file///nujogolemijusabarot.pdfIn PDF document text
    • http://tivati.com/uploads/userfiles/file/40245952046.pdfIn PDF document text
    • https://subarini.ro/mm/file/xugawajutuputugowam.pdfIn PDF document text
    • http://patroha.hu/file/75352280930.pdfIn PDF document text
    • http://eszixv.hu/ckfinder/userfiles/files/nulidelone.pdfIn PDF document text
    • http://unionnutritech.com/upload/files/51530805237.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///52769733755.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/bs8tb8hl0donmt77nali4u92ao/dosigupitinod.pdfIn PDF document text
    • http://gibisch.com/files/files/91302940901.pdfIn PDF document text
    • http://drivescuolaguida.it/userfiles/files/88540848239.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/160845ab795419---sogubojeju.pdfIn PDF document text
    • http://swhos.com/upload/files/93149429788.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/nazifep.pdfIn PDF document text
    • https://homeaestheticsllc.com/wp-content/plugins/super-forms/uploads/php/files/a78333e97dbb76fe5ffef0e45f554dbf/67033280500.pdfIn PDF document text
    • http://nuk-amro.de/userfiles/file/36796163836.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/muwekixu.pdfIn PDF document text
    • https://kenkochaya.com/user_data/ckfinder/files/3857142344.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/30dda2727600ea0d97ab397232daa9b2/76638351873.pdfIn PDF document text
    • http://kernenshepler.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/feged.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/0gb0dko1lkd3oanu9c1fntc66a/bozotinubavagifokakuv.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5f28efe5e---4301682707.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=negative+effects+of+globalization+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_off0001067a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1067A 17072 bytes
SHA-256: 2237473aefdb45bd02d61f96743cb766ed5af39ac3612091e462ef7c87514dc3
font_01_sfnt_off000132bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014ad3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14AD3 10936 bytes
SHA-256: 475dbc2369cf08b045fb305e16c0e60f2981979d41407f73e2b53643c567efa7