Malicious PDF — malware analysis report

Static analysis result for SHA-256 99d110df15725596…

MALICIOUS

PDF

75.6 KB Created: 2021-09-13 12:00:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: d7c921a58269fe7cd0580d1efd196ea9 SHA-1: 663eaa2f5c2df416c71bd1a4d7b332eb83c971ab SHA-256: 99d110df157255964cd1b341c7e2ab22bbb6ad48bce1c5736a388a1a8b49b6e6
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting, indicating a malicious intent to redirect users. ClamAV detection and ML classification strongly suggest this PDF is a phishing or malware distribution vehicle. The presence of multiple external URIs and link farm characteristics points towards an attempt to lure users to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613255b51af63---63190839125.pdf In PDF document text
    • http://tobn56.com/UpFiles/file/fenonuxivopot.pdfIn PDF document text
    • http://xn--rssx31a7tec6p.com/upload/userfiles/files/20210906011221.pdfIn PDF document text
    • http://china-baby-clothes.com/d/files/nevoxetu.pdfIn PDF document text
    • http://iuoooo.com/filespath/files/20210901042809.pdfIn PDF document text
    • https://xnkvinatimex.com/uploads/files/38797732364.pdfIn PDF document text
    • http://inercial.es/uploads/files/rutiduvivavamijadi.pdfIn PDF document text
    • http://marketingnews.fr/images/file/kabazat.pdfIn PDF document text
    • https://congnghieptauthuyvietnam.vn/upload/files/kekelakamexebo.pdfIn PDF document text
    • http://przystaneknida.pl/data/aktualnosci_imgs/file/59445180005.pdfIn PDF document text
    • https://searchkar.com/ci/userfiles/files/mesolixonuvagezagir.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/161328a97ee5fd---78526785223.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/69811855063.pdfIn PDF document text
    • http://hybsch.it/upload/file/43841191091.pdfIn PDF document text
    • https://umutfm.com/resimler/files/52091569950.pdfIn PDF document text
    • https://www.horisunmauritius.com/wp-content/plugins/super-forms/uploads/php/files/b0950fe1f7b5c32506940bf44afc0f28/ladun.pdfIn PDF document text
    • https://numen-wow.com/userfiles/cloud/files/sikak.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/jezuv.pdfIn PDF document text
    • https://thepainter.asia/upload/files/44361450312.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/1613193fe8adb5---1790753648.pdfIn PDF document text
    • https://motodubai.com/uploaded_images/files/jewodijabadiwijafolumam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=turbofly+3d+apk+downloadPDF 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_off0000c34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC34E 17344 bytes
SHA-256: 7d3d72fdfb570beedf64defca6532003c70f97619b8b56d9d79af08aff2783b7
font_01_sfnt_off0000f0bd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0BD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D4 10668 bytes
SHA-256: 2b843e509114e8e3382068e61b22cf13878fb2ef3a6bc98798627a9c78ac0e27