Malicious PDF — malware analysis report

Static analysis result for SHA-256 74ca23a756f10127…

MALICIOUS

PDF

87.2 KB Created: 2021-07-03 01:04:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 2b71c7527e7888617dfaffd02c380846 SHA-1: db526fe5252e831496e5417a21cd2abc8384045a SHA-256: 74ca23a756f101270862f164b70e3bfaa1f1f355ad52551fa6eb9449de01c227
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript and a large number of external URIs. Several heuristics indicate that these URIs form a link farm hosted on compromised websites, likely to distribute malicious content or engage in phishing. The ML classifier and ClamAV detection strongly suggest malicious intent, with the embedded JavaScript potentially serving as a downloader or exploit loader.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://arserwood.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210516232459230300mnreun.pdf In PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2735a8c31c---vojotitezejunitapu.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/gumusolugomodovofipo.pdfIn PDF document text
    • https://harkakotony.hu/UserFiles/file/82858016347.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16076a83e9f373---xibaririxev.pdfIn PDF document text
    • http://dulichgiahy.com/upload/file/remow.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b13e0f6f633---68393380156.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/91974585912.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160847cb98ba58---71239895547.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/fifajepaxivajivutiva.pdfIn PDF document text
    • http://jmk.kr/ckfinder/userfiles/files/zakojarabeweluxefurosag.pdfIn PDF document text
    • http://praguetransfer.com/files/file/webosiwalatavegewukum.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/nkpahicnc8m4al5vqangsga5c5/zulebome.pdfIn PDF document text
    • http://bulk-supplies.com/userfiles/file/10331294564.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/padowokifafuf.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/cc49sq1v8khos957biscrg6k53/27707931612.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/ad66ba043ca2d361d728c8a2487516dd/gepenerujofuximeja.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/mowasukikumupuramafudebu.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094756952750---sopifuvipewoba.pdfIn PDF document text
    • http://steelbo.com/uploads/admins/u0/files/20210531003708.pdfIn PDF document text
    • http://ateliergermain.net/sites/default/files/file/vunovorujezewagasoweruj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=india+vs+england+streaming+on+which+channelPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF51 17908 bytes
SHA-256: 15c574414d701a4da92075a8fdb7bff63d228fea0f1b574a23a950f69b89a87e
font_01_sfnt_off00011ea0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000136b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136B7 10920 bytes
SHA-256: 909d32a5f1024ac00021e941094305678274f627b8f8eabd963191e3238693ac