Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8137fae4f69e513…

MALICIOUS

PDF

84.5 KB Created: 2021-09-08 06:49:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f77b5f73f0fdce3dc293013c33d42376 SHA-1: 72afcb6a4dfd7c60405c68da451fe2494769dc30 SHA-256: a8137fae4f69e513eb3ce3be03c1fe69e797bf97db46722697d9850b20779f79
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on compromised WordPress sites or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. While no scripts were directly extracted, the PDF structure and embedded URIs are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://queure.ru/uplcv?utm_term=nom+004+expediente+clinico+2018+pdf PDF link annotation
    • https://galedo.cz/www/data/cms_files/files/busejolewigovekewurosorok.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9879d390b1---dadasin.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/27993704461.pdfIn PDF document text
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/mueks9fp2ttmr0pgptm40gmrfs/xufuduvanopuf.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/saxujaxinoluwosad.pdfIn PDF document text
    • https://vntdc.com/upload/fck/file/todezidun.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/torakusubekev.pdfIn PDF document text
    • http://divapharma.com/uploaded/file/48813237735.pdfIn PDF document text
    • http://khunghinhdepphuctin.com/media/ftp/file/94152732233.pdfIn PDF document text
    • https://goodline.by/userfiles/file/xewanipikezeloline.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a445e830ced---vifutedofunidimumutuv.pdfIn PDF document text
    • http://quiltingacademy.net/fckeditor/userfiles/file/womesem.pdfIn PDF document text
    • http://innospectrum.eu/hirlevel/file/2360237706.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/51404983610.pdfIn PDF document text
    • http://halaljones.com/uploads/files/fenifabanopox.pdfIn PDF document text
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/9d285d92491549f94376b07708338b45/7481623480.pdfIn PDF document text
    • http://hkalc.com/userfiles/buvigufedurabe.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a03777dc526---pewalavew.pdfIn PDF document text
    • https://lalicorne-hotel.com/userfiles/file/30152470823.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/38600d3b9f89a3bba347bcc6018a6ef8/91751737076.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160c16fc0571ad---sixoniserilimakabuzazi.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/8658962764.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/91011705879.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_off0000df4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF4D 19648 bytes
SHA-256: 0472ce6792c9e6867fba3ea873c8805186d7e75a5e720f82f6c16a7e7fd8c1d4
font_01_sfnt_off00011236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11236 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012a4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A4D 11012 bytes
SHA-256: ef98438d4092a405f238a06e7c1da1abc1496a82a2b671411cd911b063c6620b