Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b4c55ce80930954…

MALICIOUS

PDF

93.0 KB Created: 2021-09-06 16:46:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: bb8d224fec4f2bc14742a93c8cd1725b SHA-1: d6945aefd3b691a1639f21185457b4d1c6a1ac7c SHA-256: 1b4c55ce8093095438aac1be5379fd2e68ac09f45b188717b280cd14544bd3c2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which appear to be hosted on compromised CMS platforms or disposable domains, indicating a link farm for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the links and the PDF structure point towards an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://crysiq.ru/uplcv?utm_term=recommender+systems+aggarwal+pdf PDF link annotation
    • http://aviteksural.ru/admin/ckfinder/userfiles/files/26054713655.pdfIn PDF document text
    • https://edgecs.com/documents/80256952210.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca8940e8e9---lajatedofoveragofapu.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4d9608cc50---papitumudo.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a37fc7da0c0---gakogibamuzesivanolifiv.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/af5c681e0959d3989e47594d441e8643/74891901099.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/8cc40381fa598dcec1d3089fabb8de9b/47151477359.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b246533c8df---16266988396.pdfIn PDF document text
    • https://sunnyvale.com/wysiwygfiles/file/6723763581.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a75e2eba34b---dulaposusotofabixabub.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf94f2dfed---zabujubigabekovexo.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/deabb801470217f0610f7a14aed873c3/17555091609.pdfIn PDF document text
    • http://dentalcenterstudio.it/userfiles/files/nagawidozegokadumuf.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f7799267d4---91715217425.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1678b53851---xugobelovamabepid.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160a051be5c5f0---zagividebiw.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/16085fc6e8da75---fodilopomedijuwesipotirag.pdfIn PDF document text
    • http://industrialdevices.in/uploads/dogaruxipirubigi.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/64176083120.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606e57d3a7198---fopinukotoniwo.pdfIn PDF document text
    • http://residencelesaline.it/userfiles/files/jebuwaj.pdfIn PDF document text
    • https://thehideawayresortpattaya.com/userfiles/files/10184045232.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/tupasuramawolep.pdfIn PDF document text
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160acb11ea6758---74141161991.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/49309386380.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160b15ce37a75a---netibolafilu.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_off000103cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011bdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BDD 18736 bytes
SHA-256: 4be23b22896c2a757b82b9ede45c45ee04ce61b9bbf9c53d70fdc30104ff9d11
font_02_sfnt_off00014cd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CD8 11116 bytes
SHA-256: f7d68049d57e547b33333a0e81c6619001b4940fa0947400fac3c21bad0d6ce5