Malicious PDF — malware analysis report

Static analysis result for SHA-256 082623ab86499df6…

MALICIOUS

PDF

72.3 KB Created: 2021-05-06 18:04:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 003eca801c94599d79a7a64641cd9ff0 SHA-1: 1a4572bd49842f08028ae0a740a82f40b0e37242 SHA-256: 082623ab86499df69f7930a92cd1758952c690adddf47f69e70039a8a3dd4a71
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file is detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains keywords related to "textbook pdf" and "wkhtmltopdf", likely serving as a lure to disguise the malicious nature of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.hausbootgeiseltalsee.de/wp-content/plugins/super-forms/uploads/php/files/euq2v2nqd6n3u2oogutpefc285/16569120635.pdf In PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f2f07b0944---rajevasekogam.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce1a65e304---7605448297.pdfIn PDF document text
    • http://mikailang.net/userfiles/file/20210503175415_1799867034.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d5c00a101f---76528024749.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/f3eae0143ea21602f64f92b658107e1b/92418592612.pdfIn PDF document text
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a8b12ad8a---xeturozurorulik.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/mubekodamadaso.pdfIn PDF document text
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16078822b8885a---14941138382.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3275af4f4---riniranivarujaf.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/07ad3f957dc182f2ed3e9dd3cc9fed52/xejutonalotimapulotisiwu.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/55h2a0k91ac0lerfnnp18uqf2j/zepawu.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f0a27eb8ae---42915779062.pdfIn PDF document text
    • https://traveltokiev.com/wp-content/plugins/super-forms/uploads/php/files/4fffcb09cbet4839df66s4du53/buwupozi.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/k8nq5sqo8i9egvl7bs61cc32i0/pawasexuzopaw.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=advanced+life+support+textbook+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000de88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE88 5472 bytes
SHA-256: e69d6ef3a5d4364923913efd8d941daad5ba3d194e503ffa59f9155e1bb275eb
font_01_sfnt_off0000f13e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF13E 10324 bytes
SHA-256: ae0414813a27c33c3893dc8cd99c856bbcb39e98a7daf66401f10be9bfc55d2f