Malicious PDF — malware analysis report

Static analysis result for SHA-256 858713ca57920ff3…

MALICIOUS

PDF

74.5 KB Created: 2021-08-06 17:21:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 5888beede60b296422304abfa44afd9d SHA-1: bf72d29d8bb3c7b67a8bb17629e2ca5c13b0cf1c SHA-256: 858713ca57920ff397c8115d8a99472dc401245f98567c1858580340162f32f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it's a link farm pointing to compromised websites. The PDF contains numerous external URIs, suggesting it's designed to redirect users to potentially malicious content. While no scripts were explicitly extracted, the nature of the PDF and its embedded links strongly suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://pixomot.ru/uplcv?utm_term=cuanto+es+14+pies+cubicos+en+metros PDF link annotation
    • https://www.sanier.pl/wp-content/plugins/super-forms/uploads/php/files/81rjtk7tgdnfs2tc6nhbpqd00g/vosasodowekarezi.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/40758654614.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b74c2594a01---xomin.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/007ce7bbfa4c89617f1c61a4cedfc8e0/lusexulina.pdfIn PDF document text
    • https://xaydungdonggia.com/app/webroot/files/images/pages/files/77006909445.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160707151618e2---doxokakoxesazup.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3528b5834e---kesalo.pdfIn PDF document text
    • http://zap-interactive.com/uploads/files/gimojonosa.pdfIn PDF document text
    • https://deconkhoemanh.com/wp-content/plugins/super-forms/uploads/php/files/gpsgp5l4s1lloe6j7q6cohcimp/meparawodilevober.pdfIn PDF document text
    • http://ciarajewellery.com/editor_upload/file/36849873099.pdfIn PDF document text
    • http://metrocars.london/survey/userfiles/files/43641557856.pdfIn PDF document text
    • http://santabruna.cl/upload/file/lununalozexijaxezuxada.pdfIn PDF document text
    • http://omatsuri.kr/data/userfiles/files/26841441315.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210726_1E112A7F353D0B3C.pdfIn PDF document text
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb31490cb2---91068472403.pdfIn PDF document text
    • http://rbtyutj01.com/userfiles/files/61093704852.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079437ac56a9---84558404484.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/defutelubimufuzep.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16085bc38a64cb---puluzos.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1606cecba9ce71---wafunipikalu.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/dofevurumule.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/0obllv5ar4l8b4khfps24uj8jd/22111181612.pdfIn PDF document text
    • http://www.louthadventures.ie/wp-content/plugins/formcraft/file-upload/server/content/files/1607d89da67b52---voralakaxazaxomete.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_off0000c0b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0B3 16288 bytes
SHA-256: 194b65fa9f32db5f17f5c5b78dfef59ec4a1c81069d1b14d593967f7bfb21670
font_01_sfnt_off0000e9e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000101fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FC 10892 bytes
SHA-256: a82f523b619e1d6423bfbe4651aed09bf86678a931048b160cd848650d3cd7a1