Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a4558d8a4a75f0f…

MALICIOUS

PDF

74.8 KB Created: 2021-06-24 21:24:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 8ee1ceaf177c505f05bd8c068b38e2df SHA-1: 5cedbe4d02c382f884ceb31c0bf3c49a1c698743 SHA-256: 4a4558d8a4a75f0fbb38b275b6588f37f88145a734e641ea9a6a88b82bcc0739
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised WordPress sites, suggesting a link farm used for distributing malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution scheme, likely involving embedded JavaScript to facilitate redirection.

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 https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1608544e02ae12---meliditetij.pdf In PDF document text
    • http://cokhiminhhien.com/media/ftp/file/99833436389.pdfIn PDF document text
    • http://pamat.ro/UserFiles/file/84713986244.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/4f18022446403c3fc267e830835aad1d/9187684503.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608eaddbe0dc5---kofevirekirafarirud.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab344275fb---38998652916.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/b603e8b8d310bd172324dec0884b5fba/19993570633.pdfIn PDF document text
    • http://henca.com/files/details/file/68409317066.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607981a90ee64---14050716876.pdfIn PDF document text
    • http://www.alexgis.com/siteuploads/editorimg/file/31884711349.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608793def2d33---tumodatekikixejubexaf.pdfIn PDF document text
    • https://nhadatonline24h.com/Images_upload/files/wufejasofazekekutosako.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/200b4bac0315f861604d361dbc9dfe5b/35146680323.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b623ae18eb2---luxowawa.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/5249321c3d7da2ebbbf82e70445e543a/kunodaragejepenowedivul.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/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=present+perfect+simple+and+continuous+exercisesPDF 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_off0000e6f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6F7 5372 bytes
SHA-256: b9f77fe8245d7a08114f46117042b8a3492454119e77082a8ef4ce96a9d3e0a1
font_01_sfnt_off0000f92b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF92B 11008 bytes
SHA-256: 1dced49ace80c36f9d66bf9b3f695abd90d4d9e1497697f9742552381fb229bd