Malicious PDF — malware analysis report

Static analysis result for SHA-256 641fde8ba557a531…

MALICIOUS

PDF

81.6 KB Created: 2021-10-11 01:00:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: dd3ed1e2b31d796ad0d2d35984bc5cf7 SHA-1: 116feb5fe2bc47c0f3c2a33a042719b4f6e887b3 SHA-256: 641fde8ba557a531f11abd1b792a45f272c011decd19691c7c21972a789272cd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF acting as a link farm, directing users to various external URLs hosted on potentially compromised or disposable domains. The presence of external URIs and link farm indicators suggests the primary goal is to redirect users to malicious sites, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://infrive.ru/uplcv?utm_term=comparative+of+lovely PDF link annotation
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613a4a8d2fcba---nakulubawejevuduro.pdfIn PDF document text
    • http://chelseafoodmart.com/uploads/files/lebunapaxirilogamof.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/6e240cca54f201088d0c2242de16243e/92932037962.pdfIn PDF document text
    • https://nada70.org/userfiles/file/kafuwuvilikilawup.pdfIn PDF document text
    • https://lsv-wittlage.de/ckfinder/userfiles/files/rigefivijafiziw.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d520142709---33403132043.pdfIn PDF document text
    • https://supzg.ch/userfiles/files/kujikodutewavumefudugox.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/33575300536.pdfIn PDF document text
    • https://mygoaltv.org/ipp/images/uploads/files/4380854432.pdfIn PDF document text
    • https://www.info-service.com.tw/plugin/ckeditor/ckfinder/userfiles/files/62254802289.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161480d79a6a49---legexunikiloterinup.pdfIn PDF document text
    • http://phongthuydotho.vn/upload/files/94831505724.pdfIn PDF document text
    • https://dom4m.de/userfiles/files/97602367146.pdfIn PDF document text
    • http://hilimall.ae/uploads/files/fomuzikoretogozox.pdfIn PDF document text
    • http://juncheng.tw/upload/files/gubodulenuwudinon.pdfIn PDF document text
    • https://trichynext.com/wp-content/plugins/super-forms/uploads/php/files/b4c41b3d0b8afe0c87a0776b9e2d60fd/85308953851.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/garejobape.pdfIn PDF document text
    • http://tavio.su/files/file/mepotelelifunemalo.pdfIn PDF document text
    • https://beaszemin.com/files/69416444596.pdfIn PDF document text
    • http://esipro.fr/userfiles/file/37142304458.pdfIn PDF document text
    • http://tuanlongland.com/upload/files/dawizawetumapovuramuzilu.pdfIn PDF document text
    • http://naturestuff.nl/siteimages/file/31367214389.pdfIn PDF document text
    • http://kamakuralosgatos.com/uploads/files/72286359894.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d058a435c2---39730974942.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://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_off0000db17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB17 10456 bytes
SHA-256: 3d4d2124be6db0d6910f36944d4eb384ffc2afeb42d502bf9ca8c6c62e8861a8
font_01_sfnt_off0000f2e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010af6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AF6 18056 bytes
SHA-256: 42e052c3656c0da8a59fadfa88a21e125ab54674b9b18297d5b3462cfa77b8e1