Malicious PDF — malware analysis report

Static analysis result for SHA-256 b31b299120eb31ec…

MALICIOUS

PDF

79.8 KB Created: 2021-09-02 16:20:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 830baccc41043edee66653ace573c782 SHA-1: ad0bf7e81fa6457e107b11162179fb813b63e750 SHA-256: b31b299120eb31ec7950ab19a6de0f302780b73ec18055948ca04f188b7be4ec
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS upload directories, indicative of a link farm designed to redirect users to malicious content. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest this phishing-like behavior. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://perles-del-beya.com/userfiles/file/sezuviwunonurafu.pdf In PDF document text
    • https://m-astar.com/UserFiles/files/dojifunolisevijul.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/vhbrjrp129tubqoce06q3eifvm/mobazijegetarovusi.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/42865168197.pdfIn PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/someditapelajuzomojeja.pdfIn PDF document text
    • https://nbretail.com.vn/ckfinder/userfiles/files/rujimamof.pdfIn PDF document text
    • https://www.mppoa.cloudlinesystems.com/assets/ckfinder/userfiles/files/20627117602.pdfIn PDF document text
    • https://riondene.ch/img/uploads/file/60346350776.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/63981788514.pdfIn PDF document text
    • http://101eyewear.com/luutru/files/mebepuze.pdfIn PDF document text
    • http://noithattamphuong.com/upload/files/tevuji.pdfIn PDF document text
    • https://tl-systems.hu/files/files/tojirazuwunozapojinuzit.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/822d4ef0d5d9ed267c439767b32054cf/perulizotunisimesezukik.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/28dbf9db32fcf6a2a36a9d3563f9678e/11048735764.pdfIn PDF document text
    • https://prcomponents.com/ckfinder/userfiles/files/bavobibij.pdfIn PDF document text
    • http://wine-paraphernalia.com/files/winep/_repo/file/zejatugekizajumotokumimez.pdfIn PDF document text
    • http://www.bewegeninarnhem.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160802314aac85---27530175188.pdfIn PDF document text
    • http://placc.info/up_image/27986561906.pdfIn PDF document text
    • http://secureyun.cn/uploadfile/file///2021073004412476.pdfIn PDF document text
    • http://poltinka.ru/userfiles/file/koxumikenogituxi.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16094b2017d69c---felaladokejudikojanu.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/f8db6f1e7e9e748f468218a764cfe549/45972652319.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c5c9be3cbaa---nozikabejodekuzegexoget.pdfIn PDF document text
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/uksoa8onksajiqek7l9dm7kufm/pelezirufotax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=tipos+de+microorganismos+en+el+agua+pdfPDF 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_off0000ce4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE4D 19016 bytes
SHA-256: 99cc19bfa6bf4a500a5ac08bc05b7e610e35301c1e0f4902fe689196ae9d6a35
font_01_sfnt_off0000fe39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE39 10928 bytes
SHA-256: 4e20abcea57cc88a9f1147de51d31247a41f6bbf9088f5cd00a7f0cb3f63aecc
font_02_sfnt_off00011748.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11748 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1