Malicious PDF — malware analysis report

Static analysis result for SHA-256 639949c7585c495a…

MALICIOUS

PDF

84.7 KB Created: 2021-09-12 05:03:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 68675df10bc705fa8cf590a752e4dc93 SHA-1: 7504722c3251b3a2ac6efafed94a1b55ed6fe2ab SHA-256: 639949c7585c495a43917222e328832e4ac15bbd72b786ca4da302c864f68924
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a significant number of external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The presence of embedded JavaScript, flagged by heuristics, suggests the potential for further malicious actions, such as exploiting vulnerabilities or initiating downloads. ClamAV detection and ML classification strongly support the malicious nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://garglob.ru/uplcv?utm_term=thebrain+android+app PDF link annotation
    • http://winkeleninzundert.nl/uploadimages/files/sakoleludetasolode.pdfIn PDF document text
    • https://kozlovka.mebel18.com/uploads/files/kavisusure.pdfIn PDF document text
    • http://lovec.bg/root/ckfinder/userfiles/files/26510482060.pdfIn PDF document text
    • http://gadkowski.pl/repository/filemanager/file/18172560316.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d2ac4d2d71---97219847252.pdfIn PDF document text
    • https://femagnet.com/upload/edu/article/file/35752518095.pdfIn PDF document text
    • http://adhdesign.de/userContent/files/20210911080053-79001521420.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/1617889251.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/cff323a40b5c935f5a7b87cb508a3f60/rokenirofurajopawu.pdfIn PDF document text
    • https://tims.ro/ckfinder/userfiles/files/difipa.pdfIn PDF document text
    • http://ayurveda-shiatsu-qigong-nice.com/upload/files/74837625463.pdfIn PDF document text
    • http://geometracosentino.com/userfiles/files/60812828788.pdfIn PDF document text
    • http://olympiad-bigben.ru/ckfinder/userfiles/files/wuvagupiduripejusuzufesuv.pdfIn PDF document text
    • http://cichanski.com/Upload/file/39849405996.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612edfa25dff2---88898512487.pdfIn PDF document text
    • http://agrocare.hu/ckfinder/userfiles/files/45588338204.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/ruzuxufibedoradipu.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/pibejodegujewebaxota.pdfIn PDF document text
    • http://powerfalcon.net/uppic/files/kidapadoxi.pdfIn PDF document text
    • http://shijijiaming.cn/filespath/files/20210912070851.pdfIn PDF document text
    • https://birgatour.mn/js/ckfinder/userfiles/files/45742598692.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/43575428847.pdfIn PDF document text
    • http://clean-ecology.com/Upload/files/91497628187.pdfIn PDF document text
    • http://inarchengineering.it/userfiles/files/71019710353.pdfIn PDF document text
    • http://igs.compcierge-asia.com/ckfinder/userfiles/files/xatunifelapex.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_off0000e795.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE795 10280 bytes
SHA-256: fd1ae73c8a9f914ebfaae9f9350ef2a9dfc6294a7ac9fb200ae6f4c592a04ded
font_01_sfnt_off0000fe58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001166a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1166A 18056 bytes
SHA-256: 088a7f58a5650399e4030f197b5cb193b64660f422b89db040279f2c51e240f9