Malicious PDF — malware analysis report

Static analysis result for SHA-256 37f1ba1fbb5e3c84…

MALICIOUS

PDF

77.7 KB Created: 2021-04-24 01:42:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 66334ef5dc2c16fddc17c16ebeea638a SHA-1: d579f46b693a828892f1d22395b1b30e50def99c SHA-256: 37f1ba1fbb5e3c84bcd092fd1796a0151c947ae1ad8f4734d704ed13fc43e04e
126 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains numerous embedded URLs that redirect to disposable hosting domains, suggesting a link farm designed to host malicious content or redirect users to phishing sites. The document body, though heavily obfuscated, contains metadata related to 'advanced functional core exercises' and the wkhtmltopdf tool, likely a lure to disguise the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://midufefew.ru/strik?utm_term=advanced+functional+core+exercises PDF link annotation
    • http://plafond.xyz/15559651860agz9h.pdfIn PDF document text
    • https://tonituligavu.weebly.com/uploads/1/3/4/8/134884188/8374176.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4482848/normal_6005774b5ec16.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375339/normal_5fcecd1101227.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482218/normal_604ba0ecc4a7a.pdfIn PDF document text
    • https://ginarelerojafu.weebly.com/uploads/1/3/2/8/132814261/8958610.pdfIn PDF document text
    • http://didazema.mypressonline.com/geometry_worksheet_answers_angles.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460946/normal_5fdc56df7c0af.pdfIn PDF document text
    • https://kinijanara.weebly.com/uploads/1/3/4/5/134585029/925609.pdfIn PDF document text
    • https://fowinojosusine.weebly.com/uploads/1/3/4/4/134495991/lababitafesedoxan.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420597/normal_602eff273962f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4389576/normal_600e0ea665c32.pdfIn PDF document text
    • http://vbnmcxz.xyz/90074340833kco9y.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374369/normal_6033d04fd572f.pdfIn PDF document text
    • http://alisabor.design/93684319075y9xtw.pdfIn PDF document text
    • http://jofifuneku.medianewsonline.com/law_dictionary_in_hindi.pdfIn PDF document text
    • http://centerverifybadge.com/teeter_inversion_table_prices5e2q9.pdfIn PDF document text
    • https://fubareno.weebly.com/uploads/1/3/1/4/131482864/1746209.pdfIn PDF document text
    • http://itmax.info/avatar_full_movie_in_english_720pc9uiq.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451752/normal_5fe5bb69599b9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462974/normal_603fd4edd0970.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4414164/normal_5fd060525b616.pdfIn PDF document text
    • http://wafixevewitope.mypressonline.com/jonafepedezavepixi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462339/normal_6019a683cb9ad.pdfIn PDF document text
    • http://gudelew.mywebcommunity.org/livimijezuvijibev.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387242/normal_5fe42e0859087.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://rikuworubit.myartsonline.com/zeduledutimamejogemukire.pdfIn PDF document text
    • 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_off0000f335.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF335 5132 bytes
SHA-256: ca8d9548012f1703d9e0f258b5514319fe9e887098d25751323053e883c45b63
font_01_sfnt_off000104c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C8 10656 bytes
SHA-256: 3527ba5ae713c0001d89d46ec9e9cc587a770f0340a9a4c8f234d5f196394f25