Malicious PDF — malware analysis report

Static analysis result for SHA-256 fda81caeace8f3b4…

MALICIOUS

PDF

81.3 KB Created: 2021-09-02 09:44:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 04894b0c6e4adee144f591fb6d5f83b3 SHA-1: 23c759bb308cca4d5d94c813bbd71a467d77bb9c SHA-256: fda81caeace8f3b405d44e17f8b7dedec4f71ccb706f806023c7403c92a8d1d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous external URIs pointing to various websites, many of which appear to be compromised WordPress installations. The primary purpose seems to be directing users to potentially malicious or phishing content, leveraging the 'writing task' lure in one of the URLs. No scripts were extracted, but the structure suggests it's designed to lead users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://allytemp.ru/uplcv?utm_term=writing+task+2+on+education+with+answers
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/fvc2ulhfvk8bschjr5re8kqijb/71963443580.pdf
    • http://xn--82ca1bkibi6eufn5bh1b7i3e.com/UserFiles/File/48790489722.pdf
    • http://agro-partner.com/Image/files/46677555147.pdf
    • https://livnica-metalurg.com/images/pages/file/12432254771.pdf
    • http://thunderstar.cn/userfiles/file/20210501072855795793765.pdf
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf1563269db---77402190460.pdf
    • http://safarang.com/basefile/files/94962094423.pdf
    • http://wonikqnc.com/upload/editor/file/1623024188.pdf
    • https://sklep-pinokio.pl/web/uploads/files/80846773657.pdf
    • https://vendax.ro/files/file/97365078674.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/4e42ca7a081d4e54311cf105d530fa09/koribiji.pdf
    • https://scheidungsrecht-best.de/userfiles/file/netigosisubinovexe.pdf
    • http://abwingscolley.com/uploads/files/fimafemazirepojekotaluwip.pdf
    • http://leinerpakgelatine.com/survey/userfiles/files/taralilo.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7c8a82dbe---ginagisumagebuvemoferowi.pdf
    • https://anjingliar.com/contents//files/40858885127.pdf
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c05b469a8a7---85301922123.pdf
    • https://an-professional.ru/img/files/file/51807801237.pdf
    • http://eventcompany.org/clients/e/e3/e30ef11cf4efe639fe6592aa37b9cb94/File/29465133805.pdf
    • http://forepic.com/_UploadFile/Images/file/tujev.pdf
    • http://electric-kernbichler.at/66584624603.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbc6.bin
908d2a4f7c288c0172fa6097c88ee30196429ea969ea44086152870ea1fe5d2a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBC6 10992 bytes
font_01_sfnt_off0000f535.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF535 16792 bytes
font_02_sfnt_off00010d47.bin
788cd360cdcf3e46bb35079c541f3f1fed5ef3c918feb402b1eed19d56456a42
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D47 16224 bytes