Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3b88a0f9ab82539…

MALICIOUS

PDF

87.0 KB Created: 2021-07-27 15:54:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 928d3a6710dd68e62d56d7fbcae9284e SHA-1: 7ee80119ac23eda63ff94b12e1befa512645ada6 SHA-256: c3b88a0f9ab82539de8c519df8d5304e9c34a66385449794b6aa48dd3a693e72
156 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it is a link farm hosted on compromised CMS sites, with a high ML score and ClamAV detection confirming malicious intent. The embedded URLs point to potentially malicious content, and the document body is heavily obfuscated, suggesting an attempt to hide its true purpose. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics strongly suggests the document's primary function is to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160708d5782177---dakeser.pdf In PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/57134805744.pdfIn PDF document text
    • https://lucky-erotic-massage-bucharest.ro/ckfinder/userfiles/files/suluzeritibiparob.pdfIn PDF document text
    • https://www.corridar.com/wp-content/plugins/super-forms/uploads/php/files/dl5eo1v8q0nmd0vmv0itlibsva/48393519662.pdfIn PDF document text
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/25eaad436f4f6f3f5e492b9dfa76b050/kofed.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/refodozukakewasofidisuv.pdfIn PDF document text
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/84ftaf863dk1r6ehfn5k4dd408/91704375549.pdfIn PDF document text
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087c70e03356---takivekefikusiduvufimiti.pdfIn PDF document text
    • http://naasschoolofmotoring.ie/fckeditor/userfiles/file/kojami.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ff5c5839f---53388839585.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0d42e6d2f61eebd7602d15876b7faabb/10369708603.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/jofegedakado.pdfIn PDF document text
    • http://thankschicken.com/uploads/files/munudal.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/4b89f3bb5295623d12d7501d5a3dd63b/nufopetonemetesavivu.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075280f30f4a---danumurimedevuf.pdfIn PDF document text
    • https://adlinefor.com/home/webagen/public_html/korn/data/file/xumomadexerotazi.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/4297710ceaf7e1dff5172a1ff6128062/91942415803.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/16dcec69fb006db75dc61e98462b6c32/70089666700.pdfIn PDF document text
    • https://afayl.com/userfiles/file/37446610454.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///fumabazux.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/t57i1086bqd7ihf6j57argt557/73268185153.pdfIn PDF document text
    • http://webhenevents.com/clients/868374/File/29968429566.pdfIn PDF document text
    • http://daebokjungdb.com/uploads/files/wiwiburelazujideno.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a2d3165873---58420648324.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+set+up+hotspot+on+iphone+8+at+telkomselPDF 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://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_off0000f0e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E7 16316 bytes
SHA-256: 1a95716763c7c1c2a5556ec25e23e9fb2575b9cba8ff4498201fd1832624e7e3
font_01_sfnt_off00011b66.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B66 10896 bytes
SHA-256: 79ed8d17571852de1f0ddb51b82effb34cf644a84fc4f91554c71ffe1212bcbb
font_02_sfnt_off00013477.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13477 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1