Malicious PDF — malware analysis report

Static analysis result for SHA-256 efb8cdc59af5d99a…

MALICIOUS

PDF

79.8 KB Created: 2021-06-24 18:57:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 3ef9f6e7c48f9ec0ccbb92ee1210e692 SHA-1: 10703b3e402df5599749db0148909300041be6f5 SHA-256: efb8cdc59af5d99a387554e6eb30ab93357f7f983629d8c5af82bda619a923f2
156 Risk Score

Malware Insights

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

The PDF file is identified as malicious by ClamAV and an ML classifier. It contains numerous links to compromised WordPress upload directories, suggesting it's part of a link farm designed to distribute malicious content or phish users. The document body, though heavily obfuscated, appears to be a lure, referencing a 'Dewalt user manual'. No scripts were extracted, but the presence of multiple compromised URLs indicates a high likelihood of malicious intent.

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://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/4c13cb1fff5f15e430a4caefe7d2d09b/91320380032.pdf In PDF document text
    • https://www.freshstartdigitalmarketing.com/wp-content/plugins/super-forms/uploads/php/files/b9f41fa7cbda55382783398ccc8bb71d/gupobufisawasibikotoma.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/09dc3bf77a834118eb96ba60f6d14f77/budadibefilujifadigifi.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160903d7021c24---balewaxisunineboda.pdfIn PDF document text
    • https://jackyrouxmethode.com/userfiles/file/66435465472.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac6da392ae---4136195036.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210504200640.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/8tfco6h63sm4mbpbk1230fkpi8/managorurowujogibokaraf.pdfIn PDF document text
    • http://imi.vc/upload/files/wisalimokunena.pdfIn PDF document text
    • http://teenaramainc.org/clients/875997/File/58984343487.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609e5dfa190ae---4465417021.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608274f06522c---58244227154.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=dewalt+user+manualPDF link annotation
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/c379df51e5856e81f08e604b3d245980/27935535122.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ee3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3B 4644 bytes
SHA-256: 1dbdf70ff4104e8600dafd7caa92669b6c7473fe812938a0c850fe21427bf3ab
font_01_sfnt_off0000fdf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDF0 11560 bytes
SHA-256: d9884f1cdd13dcf952fb72bc61bd9ed37801eb76a6e5198574e44b9dacf8e3b6
font_02_sfnt_off000124e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124E0 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378