Malicious PDF — malware analysis report

Static analysis result for SHA-256 efca8bc155a336b8…

MALICIOUS

PDF

86.5 KB Created: 2021-07-30 21:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: cc2123c7f47127b34d7bf723b836197d SHA-1: 033c91612874a86f5df48c94d2dc7fda86b7c162 SHA-256: efca8bc155a336b879b98c24c0e1c8ca2bd22513512427e7505b0c4445c4caa4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting it functions as a link farm to distribute further malicious content. The presence of embedded URLs and the nature of the heuristics strongly suggest this document is part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://nomylo.ru/uplcv?utm_term=math%C3%A9matiques+3%C3%A8me+exercices+corrig%C3%A9s+pdf PDF link annotation
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/1e340694d7b6c3592ff026cb6a5668e5/wiraxejuza.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/39634556595.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/35224279395.pdfIn PDF document text
    • http://batiment-tunisie.com/userfiles/file/6265428947.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/2vigr158g1jvp7nknc728omoob/51152742720.pdfIn PDF document text
    • http://chunmianxian.com/upfolder/e/files/20210728121905.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160821084ccc5c---9675514942.pdfIn PDF document text
    • https://angelsstaff.com/uploads/file/47764676684.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/7rr4pm9jlpli32nu2222dle90s/68557866158.pdfIn PDF document text
    • https://414movement.com/wp-content/plugins/super-forms/uploads/php/files/f1f1c4fec9071e13d50c039f9ab6b97f/50203927790.pdfIn PDF document text
    • http://posekatzahradu.cz/files/file/95656754813.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/vopulisikizumasut.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5bb691c65e---putebugidu.pdfIn PDF document text
    • http://curry-box-deluxe.de/userfiles/file/25851828683.pdfIn PDF document text
    • https://gw21.ch/uploads/userfiles/file/pobifezinevu.pdfIn PDF document text
    • https://tailormade-sales-marketing.com/userfiles/file/58025293375.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cb2ba619b6d---67796085298.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/b4cde022c08eca59eef7b7070921b647/85091269082.pdfIn PDF document text
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e50ba4f3c8---2758363258.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607c308938dde---10330569942.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9f4cbe3d88---21983044630.pdfIn PDF document text
    • http://odesignlab.ru/admin/ckfinder/userfiles/files/sidiwimaxokapapipuw.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16091e4ac0fad6---jabefiwimitaxeje.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/8be7853c830d50af369d43fdc5f57dd3/60629893038.pdfIn PDF document text
    • http://dailyxedayhang.com/userfiles/files/20497640064.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_off0000edee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10600 16128 bytes
SHA-256: d37f4050a6f843cac0e42868959d362d200f0c330ec23a1fe04d553366b02e6e
font_02_sfnt_off00012e4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E4F 11740 bytes
SHA-256: 5e067bf4bf3e60b4201b7cb2a15496f99b975ab7c34e4d3efd4c6aa5c968dcd5