Malicious PDF — malware analysis report

Static analysis result for SHA-256 39c811a9f86ed995…

MALICIOUS

PDF

85.4 KB Created: 2021-09-10 19:26:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 108d6e71533f95b81cad523ab600e1e6 SHA-1: 2d6c2d470c27a44c987dbd5c2bb18a6bbd99f43b SHA-256: 39c811a9f86ed995fb052f518f38a49ad279063ebead7016a42c333bc6b043be
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various domains, many of which are identified as part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, preventing a more specific analysis of its direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://riminabda.sk/userfiles/file/95582162163.pdf In PDF document text
    • http://mycoapaisyl.com/webimages/files/dukiwajagivuzubuzadux.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/levonubaf.pdfIn PDF document text
    • http://wx-test.com/upload/ckimg/files/202109081647547623.pdfIn PDF document text
    • http://roocenter.ru/upload/file/70823650968.pdfIn PDF document text
    • http://saraya-shop.ru/upload/files/52371788389.pdfIn PDF document text
    • https://lederstuhlshop.de/ckfinder/userfiles/files/1605318029.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/zeriruwosib.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/vagetoz.pdfIn PDF document text
    • http://kunmobile.vn/files/uploaded/20210904/file/25280235030.pdfIn PDF document text
    • http://mjacz.cz/soubory/files/44392835310.pdfIn PDF document text
    • http://er-trans.com/img/produkty/files/virizudasadete.pdfIn PDF document text
    • https://weborder.cloud/userfiles/file///61366042902.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/pupodotigipofomategibikop.pdfIn PDF document text
    • https://byocamacho.com/ckfinder/userfiles/files/dulunosezunikapawi.pdfIn PDF document text
    • http://ciaomamma.hu/editor_up/86061098289.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/99580552697.pdfIn PDF document text
    • http://predit.ru/admin/ckfinder/userfiles/files/ritelofutajob.pdfIn PDF document text
    • http://millionsdiscount.com/mo_images/files/jaropim.pdfIn PDF document text
    • http://tetobox-budapest.hu/uploads/files/19470250272.pdfIn PDF document text
    • http://edukoc.net/userData/ebizro_board/file/veraxanufokelila.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131a060d3055---jowopaxuvizi.pdfIn PDF document text
    • http://op-gold.com/ck_image/files/bilirikajefisalu.pdfIn PDF document text
    • http://sherwoodonionfestival.com/ckfinder/userfiles/files/68503294671.pdfIn PDF document text
    • http://tid.vn/upload/files/gigekevemapezis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=pdf+notes+androidPDF 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_off0000ec2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2E 10300 bytes
SHA-256: 92e7bb971a98079bab76e8f65e087b12d094f01828dcce3edc88d5e0da479796
font_01_sfnt_off00010389.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10389 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011b9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B9B 17144 bytes
SHA-256: b75e9fd9a471e89ee4498cd199bd1d63a5ed23da0151d8ff1dc8ad0d5ae0ae5f