Malicious PDF — malware analysis report

Static analysis result for SHA-256 139b6e48c58d0fa4…

MALICIOUS

PDF

71.0 KB Created: 2021-05-10 23:00:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: ae637358be5d224008a4809db3045344 SHA-1: 217c50b8e788770f76bd9dbb5501835303a81171 SHA-256: 139b6e48c58d0fa4d558d7d49fe7a7da788bf53521a249914efaac0c10fbb72f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a link farm hosted on compromised websites, designed to trick users into downloading files. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing and trojan activity. While no scripts were directly extracted, the presence of numerous links to PDF files on compromised CMS uploads suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://ezibra.pl/upload//file/10753835240.pdf In PDF document text
    • https://www.dynasil.com/wp-content/plugins/super-forms/uploads/php/files/f136174d9f195ff8600437048069ef85/legajopiwopuwujevevirutap.pdfIn PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/vqk482kan96d9t07m6e7b4asm5/kizapujumejabasuwup.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607121c08386d---xedafifujipof.pdfIn PDF document text
    • https://www.rydalmereprestige.com.au/wp-content/plugins/super-forms/uploads/php/files/3i2dn2b5klpoi6v6jtcu1c7t8a/mirugi.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160948792a136e---bojusuwapadatojupot.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/8685ffd0093275a576cc855d3b45d1b0/15601654014.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/292fab491193511023518637989ff467/70495960049.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/0335e80f392da1304cb29dff65dd401d/tuwewipidupezedurokizolak.pdfIn PDF document text
    • http://www.guaitoli.eng.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4fdf18735---ravirufad.pdfIn PDF document text
    • https://sckprime.com/wp-content/plugins/super-forms/uploads/php/files/b03645ad43a642a8b1c29274ac4b649f/6693434688.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e0a9609002---29494192188.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/160968f80d968b---25881131198.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609434f251ef0---91112316054.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/pojonezixiwuwamu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=cisco+packet+tracer+6.+3+student+versionPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d709.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD709 5416 bytes
SHA-256: ea8ebb4d53fd98fbc86fd6fdfcf3573d15ba4df7ac16f4f0e9ccc68fba785c49
font_01_sfnt_off0000e98c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE98C 10888 bytes
SHA-256: 24c533341bf47ce8e367a22b06c8d285f28c93c590b5ec59f3f3e6f021d87fc9