Malicious PDF — malware analysis report

Static analysis result for SHA-256 4fd531471286eeba…

MALICIOUS

PDF

87.6 KB Created: 2021-07-01 19:51:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6a29147e35ebe8faa27127c65fd6841a SHA-1: 58e5e04ad312ca1235c142b8b8a0ddceda69885d SHA-256: 4fd531471286eeba7a73eedbaf9e0d9b64d83d2bbab3975c5d1425b835c23ea3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. Multiple heuristics indicate a link farm pointing to compromised WordPress upload storage and disposable hosting, suggesting an attempt to distribute further payloads or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/9ei2dop4v0mggo35h4udrq0egm/52838999140.pdf
    • http://alkanboya.com/files/file///zekadimutasazivazafurufi.pdf
    • http://muzeumostrowiec.pl/obrazy/file/lobugedamaniburisuj.pdf
    • http://fecoil.com/userfiles/file/sagewewaxexazosa.pdf
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/3d175d97d3c7226a2bd0ef86fb8e1fce/96262748823.pdf
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/qvk27349ecpio9k7jh05k79hj1/66654946854.pdf
    • http://firewheels.pe/userfiles/file/9022758075.pdf
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/ha29hs0605dhki5h5bp3hdqorr/72108324965.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a673962f72d---mebupunawafagovod.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/ta7mn5f5fhq7ln614qipkqbui3/97804049442.pdf
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/3d6b12821ee430589469fe219e314c53/fonojuzu.pdf
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/37f21e11b968103e349ff0d6dc8aeba3/3365961629.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608491471f862---60340743600.pdf
    • http://electrogalicia.com/electrogalicia/recursos/archivos/mozegawa.pdf
    • http://skyrun-arser.com/js/fckeditor/editor/filemanager/connectors/php/connector.php/upfiles/file/210612122918218726vyg82p.pdf
    • http://ahkjt.com/upfile/file/90519574984.pdf
    • http://dnepropress.net/files/file/368767492.pdf
    • http://bigxra.com/uploadfile/file/2021052018210973499.pdf
    • http://homenet-spb.ru/userfiles/file/66723184589.pdf
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/71f7tit0kso1qrovrpku5iq3a1/51363098328.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=describe+your+neighborhood+using+interesting+words+and+phrases
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f24b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF24B 16792 bytes
font_01_sfnt_off00010a62.bin
1a2426b4709099dacf7bd4204327f997bcf3fb3b037d7b3aedfe9b643a2afbd5
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A62 11188 bytes
font_02_sfnt_off0001243a.bin
27bfda9199b73e4f554e272d15da0e32bde4d087be335c4f134ef63f21619865
pdf-font-stream PDF embedded font (sfnt) at offset 0x1243A 17124 bytes