Malicious PDF — malware analysis report

Static analysis result for SHA-256 393f41fc78f0b2b0…

MALICIOUS

PDF

88.2 KB Created: 2021-09-16 00:55:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ee253d0cda9f589f7a4211821dd74656 SHA-1: 1d9b2935a61548688a32c21727aaec2e82b73751 SHA-256: 393f41fc78f0b2b06fbbdd9dc0641dfbc8b49752c21c8b9c805508e852e40c5d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. The PDF contains numerous embedded URLs, many of which point to unknown or potentially malicious domains, suggesting a phishing or malware distribution attempt. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it is designed to redirect users to external, potentially harmful, content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://jiu-hang.com/upfiles/editor/files/90782196784.pdf In PDF document text
    • http://kfgame.snailgame.ru/upload/files/20210906225838.pdfIn PDF document text
    • https://tolgyesvolgy.hu/userfiles/file/velawimexijesala.pdfIn PDF document text
    • http://consade.com/userfiles/file/nevisiterozavu.pdfIn PDF document text
    • https://equinox-e.com/upload/files/nepifunoroxobedi.pdfIn PDF document text
    • https://matraci.info/UserFiles/File/ruxevagiv.pdfIn PDF document text
    • http://ekmeta.lt/failai/file/57040019894.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/13680181990.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/11201909103.pdfIn PDF document text
    • http://interstyle.org/content/xuploadimages/file/69613329152.pdfIn PDF document text
    • https://momentous-inst.com/uploads/image/files/44454356667.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/tofafemogaxe.pdfIn PDF document text
    • http://villabrown.it/userfiles/files/zufuwaxewopoluvelesimib.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109130500078007.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/78011233081.pdfIn PDF document text
    • http://officinedesign.it/userfiles/files/jetufidezirurolu.pdfIn PDF document text
    • http://densayhongngoai.com/uploads/userfiles/file/taporipuxigup.pdfIn PDF document text
    • http://starcity-vinhomes.vn/app/webroot/img/files/65414353946.pdfIn PDF document text
    • http://www.sbawerribee.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613b3763c1297---kutuxadale.pdfIn PDF document text
    • http://pro-customer.de/userfiles/file/49202166369.pdfIn PDF document text
    • http://k9careclinic.in/ckeditor/ckfinder/userfiles/files/levefuvimoladitel.pdfIn PDF document text
    • https://kultmotor.hu/images/files/telegatebudil.pdfIn PDF document text
    • http://xn--365-pn7mwb654m2qn.com/ckupload/files/70256402342.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=small+is+beautiful+schumacher+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_off0000f2c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2C2 18188 bytes
SHA-256: 5ddd5998dd8d7f7fea21a20d41d5b0332566f790e35d4e91e57fcb448538af61
font_01_sfnt_off000121df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121DF 10976 bytes
SHA-256: 0806b2a6d6dcd3711d578b80a7b18aed534d2fa5f278605b226cf6c2408935a0
font_02_sfnt_off00013b1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B1B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1