Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c94124d5eee9b1d…

MALICIOUS

PDF

84.1 KB Created: 2021-09-06 15:58:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 266b8f4274ea783063f7d261314b0a40 SHA-1: 9a0741ba21049b2bd57ddc6ee440b096aa41fbc9 SHA-256: 8c94124d5eee9b1d37d3c5bbcbf657dbfe4dfd7fc865b9810fdc24fe6dac35a2
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to download a second-stage payload or redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/c5b0790226a31de74788cfa449860bea/79467124519.pdf In PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/68a91dd4da569c2d4567c64d229207f2/wubexog.pdfIn PDF document text
    • https://tungqibiotech.com/upfiles/editor/files/18347295132.pdfIn PDF document text
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/1958f66c0eb4ceea3a628cf0176795c9/67802106602.pdfIn PDF document text
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/8vlic23iidpjuggftgh06elqqf/37494840521.pdfIn PDF document text
    • http://apricomm.com/userData/board/file/50011429264.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160915f7d665e5---54866588215.pdfIn PDF document text
    • http://volamtuyetthe.com/userfiles/file/lonuvakedujake.pdfIn PDF document text
    • https://matfreklam.com/calisma2/files/uploads/40864427542.pdfIn PDF document text
    • http://polyalpan.hu/_user/file/sajedigumaxidugi.pdfIn PDF document text
    • https://valerart.com/ckfinder/userfiles/files/dawimeg.pdfIn PDF document text
    • http://viorina-deko.com/images/file/73969714594.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/7b66188744d2a80fed7c46516a82e50b/dasasolotisavaf.pdfIn PDF document text
    • http://cipetbhopal.com/webimg/files/6952242348.pdfIn PDF document text
    • http://www.gesas.it/media/mailinglist/file/1445952300.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/xuwovesetatogojor.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1607d49b563899---78025442407.pdfIn PDF document text
    • http://firanywiktoria.pl/uploads/editor/file/60021029491.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__610C15C91B00C.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/e1e30210a686909ab5a590567cef9a0b/28046784759.pdfIn PDF document text
    • http://stlnsk.ru/uploads/file/xepinaroluv.pdfIn PDF document text
    • http://mtprospectbaptist.org/clients/7/74/74f10a8404da00fab064704771972c19/File/ribeginifisazutiniseba.pdfIn PDF document text
    • http://blackshirts1962.com/clients/f/f2/f245580d3072b78cda2271cf7a7e3f61/File/10143370976.pdfIn PDF document text
    • http://designbeginnings.com/upload/file/3945561601.pdfIn PDF document text
    • http://langmoon.jp/js/upload/files/xiwazibakunaravivatupa.pdfIn PDF document text
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/01194d17086375222ffe0569c5abcfbb/jezuvedaturoxowuzup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=citizenship+test+questions+and+answers+2019+pdfPDF 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_off0000e245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE245 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fa57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA57 17364 bytes
SHA-256: 9a641767dc443cf20ffacb52d11dc1a290d86d401700de8ec8665ff6cc339c4f
font_02_sfnt_off00012715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12715 11432 bytes
SHA-256: a155e5cc0305aceb2a3f88d497a38baddba9d3fd34c304bc3b58e97367d3770a