Malicious PDF — malware analysis report

Static analysis result for SHA-256 73911a0cbc25cfe4…

MALICIOUS

PDF

94.5 KB Created: 2021-07-31 16:20:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 73a2f17c3f4caacef75bf2c18b310cac SHA-1: edeefb91ae6da5b24174d3236998cbc0defd6501 SHA-256: 73911a0cbc25cfe4af098944aca4f36d850f8ceb3e22a0c025c4d4a5f0ba8634
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the overall heuristic firings strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://infrive.ru/uplcv?utm_term=lista+de+exerc%C3%ADcios+sobre+%C3%A2ngulos+complementares+e+suplementares PDF link annotation
    • https://luathoanghuy.com/uploads/files/66621054511.pdfIn PDF document text
    • http://barksdalereunions.com/clients/869108/File/nedanoxupilomutu.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/sivejalopaboka.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609eed0082648---nitemipajapukokev.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/2eae6f66fb454e3f3fd0f9b2126c9529/vawawuxojenawa.pdfIn PDF document text
    • http://khocabien.com/uploads/files/46185092214.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/30919438b4efdef2984ff1532ef57f41/1611531664.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ffbb6e4263---55965657723.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/73533250874.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606c9e5a9b1c0---75432273156.pdfIn PDF document text
    • https://tuttoadomiciliocn.it/file/73792099385.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/160bfcb8143e14---fadokape.pdfIn PDF document text
    • https://tezerwatch.com/file/upload/files/07-30-13-54-33-71.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160864b6fea721---lowufebux.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/f06141c064f414ec21dc6e1bd775f1c3/68575813171.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f26cec68e1b---pinemevigoravem.pdfIn PDF document text
    • http://interwork.sk/userfiles/file/69684307455.pdfIn PDF document text
    • http://nt-module.ru/ckfinder/userfiles/files/rojelum.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/7d8l1cdffcaim6nj258fqa7s66/bowigujafaneno.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/16079ec880e861---poxatunofavot.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/cb31ca47fd64422231f681fcb830f08d/45311398892.pdfIn PDF document text
    • http://draftingfloorplan.com/ckfinder/userfiles/files/207291280.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160dc9ec144c5b---bepizekivagilaf.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_off00010559.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10559 11408 bytes
SHA-256: 11f392f2f277d760f62885070d90891a8c9bab44bd4935a8ea9227e88b498b0d
font_01_sfnt_off00011f6d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F6D 19796 bytes
SHA-256: c9dc323fdf67dcc271c1d14bda8b9edfa090917f342a3ec03379032286c64b8d
font_02_sfnt_off0001500d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1500D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1