Malicious PDF — malware analysis report

Static analysis result for SHA-256 2b6ece0405478af2…

MALICIOUS

PDF

74.2 KB Created: 2021-05-10 05:26:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: a01084361afa066250ab6d9020cba638 SHA-1: bfc906ea01bb3067bd77890f217e459d146d1448 SHA-256: 2b6ece0405478af2cbf901d1ac5939992f43a270987e5ee3b1c0e508ffeefd9a
96 Risk Score

Malware Insights

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

The PDF document contains numerous links, many hosted on compromised WordPress sites, suggesting a link farm designed for SEO poisoning or phishing. The document body, though heavily obfuscated, references 'Coursera machine learning quiz answers week 1', indicating a lure to attract users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/7df7cbefad0aaf2be344fce3f216514a/rawezexuge.pdf In PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/nhtkqiv0l9jd3sf929aue23g13/betaxogujimumix.pdfIn PDF document text
    • https://www.lightingsolutionsal.com/wp-content/plugins/super-forms/uploads/php/files/056a0b10ee6a861466520457e56f8700/gobariwekisagofival.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608005ea64266---vowonawaf.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/1609119c4baf14---xufegalovejadojavo.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/160988c71933e0---95156004970.pdfIn PDF document text
    • http://fashioncenterpoint.com/wp-content/plugins/super-forms/uploads/php/files/0b6dd2dbe26667d7b11e6f2867503cdd/tadeworekazokuwi.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f655e98d4c---bumolukewipenasuvutizi.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16090e923899ed---moruxikuf.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/16jg4c3les0320f5apop2209sm/44106733495.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/95370aac9c1f2bc78751b76b593f29ce/rewipi.pdfIn PDF document text
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/vavimutikumumotadu.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16080b9a69d104---25548958481.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/16082e3171961e---56130028778.pdfIn PDF document text
    • https://lightingsystemscol.com/wp-content/plugins/super-forms/uploads/php/files/9493a6540adcf4e537b422354c5aea1a/zupunolubo.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/ebb95b5bbd104e7f571b3c28ab4f4c79/kusupagiwipolanakere.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/69102345654.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/vimebenirewazemiwo.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/9e1dd31ef347d478ca37012e9e85bc6d/68345018514.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/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=coursera+machine+learning+quiz+answers+week+1PDF 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_off0000e21e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE21E 5504 bytes
SHA-256: 906792a0b200f62ee587fe80898d4a4a6830c7e1d9f795c4ce0fa0200a0c7dc3
font_01_sfnt_off0000f4c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4C2 11428 bytes
SHA-256: 5b36ee23dd2c4785a3bc7f4112f3df1aa0d7ec2bc0250f294ad54b3f344d95a4