Malicious PDF — malware analysis report

Static analysis result for SHA-256 4afc33ed29b7b948…

MALICIOUS

PDF

91.4 KB Created: 2021-04-28 10:25:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 0516446cdb956bd7a327da8d563669a1 SHA-1: 03e03436331bed050aaad5d21bc54df92db8924a SHA-256: 4afc33ed29b7b94816abdb04bb6cee05fb6eab5d56a204e5db6ecf56ce0ab6ae
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to distribute malicious content. The document body, though heavily obfuscated, appears to be a lure related to 'Gcc gnu c compiler manual reference', which is likely a pretext to trick users into visiting these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/65ocq4o73vg5i0p3jm3vb900f3/deteju.pdf In PDF document text
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/de80aa9ccfc676dea29754aae00a540b/37768490900.pdfIn PDF document text
    • https://www.movingwithmagna.com/wp-content/plugins/super-forms/uploads/php/files/d08cce5ba029d31870cb92f0c9f9be52/suwonaxelabid.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070137dc6e88---tesuwelo.pdfIn PDF document text
    • https://realestateconnect.us/wp-content/plugins/super-forms/uploads/php/files/fvl5lr9irtn0enbv542ifj4h75/47721545399.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/6ef5e1c826778bea59ab4d75917dc68d/19309973454.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/16071d9c3478d1---80237790535.pdfIn PDF document text
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/48033b2412c74748d9177a526f675ecb/pasifidobinokusinijemub.pdfIn PDF document text
    • http://www.fullertherapy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747d60d3940---tufarag.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16075e0ca8a170---wevixokijaramafe.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/7cbbd1ab89d869e5d5ceca9a722e553b/27567169240.pdfIn PDF document text
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/03669259ef3fced1067157d3f40dce86/zamabomugize.pdfIn PDF document text
    • https://iescolumbus.org/wp-content/plugins/super-forms/uploads/php/files/be6342c127c0236fd9a76296e684410e/worolowanuterojojafo.pdfIn PDF document text
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/e73de419b10b6bc4b0d01ab1190f11ce/29120324914.pdfIn PDF document text
    • http://devdoc.netIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=gcc+gnu+c+compiler+manual+referencePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000128ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128EA 5188 bytes
SHA-256: d89214bf2d01594008fce005e4998fd33ae26c5878e14ab475820583eda286f1
font_01_sfnt_off00013a86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A86 11268 bytes
SHA-256: 329fcc00a8c4f40d427982ddf24cf4dcad78d20e027d67f29d5a50c46cdd2803