Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e8821a73ca4e3f9…

MALICIOUS

PDF

75.1 KB Created: 2021-09-15 18:35:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 54a9c5d887b3b6570c205b891d6bb1f3 SHA-1: 6b352dffe96963a505c2b02edf069236ffd08956 SHA-256: 4e8821a73ca4e3f9e335608f064fc2222cff8a0cad220dacb91aad6f2755c4de
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics strongly suggests a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=hogwarts+mystery+mod PDF link annotation
    • http://www.contectrade.hu/fckfiles/file/bokagup.pdfIn PDF document text
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/49235339105.pdfIn PDF document text
    • http://shlawllc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/6568092542.pdfIn PDF document text
    • http://mayepnuocmia.vn/data/ckfinder/files/50706652095.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/35784661390.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/33968722959.pdfIn PDF document text
    • http://neuchina.org/userfiles/file/dokajozuze.pdfIn PDF document text
    • https://kipass.fr/userfiles/file/87066529800.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/ca6a3eb531a8c67f1c33ae9c28342099/soxonaxuxineraredeze.pdfIn PDF document text
    • https://lacgl.org/upload/editor/file/jevufuzexefubimubojewu.pdfIn PDF document text
    • http://jawarakreasi.com/file/26048941734.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/50585304267.pdfIn PDF document text
    • http://abwcoliseum.com/uploads/files/vekatovuwonota.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d37053dc7b---zezubolugij.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ede528f5a5---85863898620.pdfIn PDF document text
    • https://epagneuls-bretons.fr/caningest/images/file/68563502429.pdfIn PDF document text
    • https://malayalamfoundation.org/admin/my_files/file/96054476322.pdfIn PDF document text
    • https://dongphuchuytai.com/upload/files/panufivedagokuk.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/45429395412.pdfIn PDF document text
    • https://buzascsaba.hu/userFiles/file/15686981684.pdfIn PDF document text
    • http://datcat.vn/2018/file/rowenasovizubedu.pdfIn PDF document text
    • http://fresh-j.info/images/uploadedimages/file/bopijo.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/36330367512.pdfIn PDF document text
    • http://isystem.hu/userfiles/file/78150324726.pdfIn PDF document text
    • http://newworldss.com/uploads/file/23171682652.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_off0000c278.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC278 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA8A 17020 bytes
SHA-256: a379c7de1e6978894e0f7458d3a0dce3a06ed3b5f8757042f25fa762a2694dbc
font_02_sfnt_off00010687.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10687 10540 bytes
SHA-256: 235fda02eb457b854a508ed7072b2bef32bb158b4490cef9cfe0ecb879e80028