Malicious PDF — malware analysis report

Static analysis result for SHA-256 c51ae611d050bd7b…

MALICIOUS

PDF

81.7 KB Created: 2021-09-14 02:11:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 7a70144dcaadb0de11fb4051ea76f531 SHA-1: c71c7802e32b7cb4627eaf38d4e951108cdf287f SHA-256: c51ae611d050bd7bd9a84b9dd57877f98103e2700a840c5ad7c0b69c3d5ade51
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs pointing to various websites, many of which appear to be hosted on compromised CMS platforms or disposable hosting. The presence of these links suggests the PDF is designed to redirect users to potentially malicious sites for phishing or malware delivery. No scripts were extracted, but the overall structure and URI findings strongly suggest a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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=hack+8+ball+pool PDF link annotation
    • http://www.thunderesp.com/ckfinder/ckfinder.htmlfiles/sovupinerane.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/3be20a798e21be378bdedd31e0ebd5d8/31249782776.pdfIn PDF document text
    • http://zhihepvb.com/upload/ckimg/files/202109131828075538.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/76834461296.pdfIn PDF document text
    • http://dagmar-e.de/userfiles/file/xabamefidi.pdfIn PDF document text
    • http://sherwoodchambergolf.com/ckfinder/userfiles/files/53807970176.pdfIn PDF document text
    • http://scouttautomotive.com/editor_uploads/system/files/52425198761.pdfIn PDF document text
    • https://szpital-sulecin.pl/images/fckfiles/file/12482261084.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/nawumonuwisozudajagegoju.pdfIn PDF document text
    • http://dymenahealthcare.com/upload/fckeditor/file/marenanax.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/wisubu.pdfIn PDF document text
    • https://lesrimaudieres.com/images/uploads/file/35952992301.pdfIn PDF document text
    • http://185.33.116.145/~acus01/upload/files/sutasifemobalememo.pdfPDF link annotation
    • http://househouse.it/userfiles/files/sazepapu.pdfIn PDF document text
    • https://a-guskov.ru/uploads/files/89211395121.pdfIn PDF document text
    • https://terracell.pt/images/file/gumulolozuweje.pdfIn PDF document text
    • http://kahounova.cz/userfiles/file/97297933931.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613147decc011---fevimun.pdfIn PDF document text
    • https://kitapkapla.com/upload/ckfinder/files/20224012350.pdfIn PDF document text
    • https://indiansabroad.uk/userfiles/file/zarujifejefisuno.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370b478ba72---47083484117.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/nerot.pdfIn PDF document text
    • http://extrastyle.ee/ckfinder/userfiles/files/1894687344.pdfIn PDF document text
    • https://negaratoto.com/contents/files/begipab.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/87ec8a38bcc2bdbfc5194e2af70fdba3/6607760491.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_off0000de75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE75 10104 bytes
SHA-256: 37ffb46baf4f45e3528e7dca2c14e870f5220435919137c7964e6b0913e0a07a
font_01_sfnt_off0000f4de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DE 17088 bytes
SHA-256: 7f6f0f0322f5540387eb53819376e837d76e71fadea7c2cabb8dd277498d76a0
font_02_sfnt_off000120f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1