Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c939373f37c7a9d…

MALICIOUS

PDF

105.3 KB Created: 2021-09-04 05:16:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 106729e2ef8cd1615ba96a8b43b3ad51 SHA-1: a237df0dcab486f7c1d0182cdb0ccbcd02a3b093 SHA-256: 4c939373f37c7a9db4f5496ebe6ae492c45fd4416f4d7851f1848635534ab3db
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, indicative of a link farm designed to host malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were extracted, the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://aftaplan.com/works/peepsparty/html/upload_files/file/lizexelubopewafatojelez.pdf In PDF document text
    • http://royalrep.com/userfiles/files/zanud.pdfIn PDF document text
    • https://www.alongsideasia.com/wp-content/plugins/super-forms/uploads/php/files/069f1233653edb75d5dab3aa740cd805/13770440488.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/44576578887.pdfIn PDF document text
    • http://j1medical.com/uploaded/file/26232546476.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/12b6b6ba0162af358eb8175ce80e23a7/vekubixulusepez.pdfIn PDF document text
    • http://supermarketdv.ru/files/file/76325733333.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/89ee146d7223c9d73ef157338cf83bae/tosevizixamujavulig.pdfIn PDF document text
    • http://africansafaris-spain.com/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/4042600900.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/428302de966aaf1fabd2bc70be334903/7343857141.pdfIn PDF document text
    • https://www.icslights.com/wp-content/plugins/super-forms/uploads/php/files/7a4948cd14b8a2facaddab3e7f5cc2c5/61286419659.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/jhhu6pb0s48ruk1tqcbrlau70m/43709954508.pdfIn PDF document text
    • http://piqiso.ru/userfiles/file/32497521072.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/92j6g01d4ciu6o42ve3551kher/zasomepakumaxe.pdfIn PDF document text
    • https://2ruoteexpo.it/ckfinder/userfiles/files/barirafegupesowukaf.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6250127ce4---88292726702.pdfIn PDF document text
    • http://1000projects.ru/upload_picture/file/95830487384.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160866d2754ff8---34510225375.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/697932189i0b4uc1k00dq43m5v/22758636219.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/ms19246kadtouoehovm838q4cn/butumevoka.pdfIn PDF document text
    • https://wecareprogram.org/images/file/vabosevubumiref.pdfIn PDF document text
    • https://dennismaloney.ca/upload/editor/file/tuwilixatedimunuteki.pdfIn PDF document text
    • https://maintogelonline.info/contents//files/22719818153.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=manual+de+orienta%C3%A7%C3%A3o+do+dctfwebPDF 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_off00012de7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DE7 11084 bytes
SHA-256: 6628179f3f45587f4a3255e6da0405d42a63b0df26819f08788a5fba3233c710
font_01_sfnt_off0001472e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1472E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015f40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15F40 22240 bytes
SHA-256: 98a8202ae804ed8f6c23e62c0b8852ccbbae5b020348295ba61d0effa211ce89