Malicious PDF — malware analysis report

Static analysis result for SHA-256 57ff7fa1a75e7abe…

MALICIOUS

PDF

124.8 KB Created: 2021-06-11 10:14:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 1529aff47801f89b0e377c7e4b1433d9 SHA-1: 48e4eb2659b8e36629ca9a0a370e8dde555c5092 SHA-256: 57ff7fa1a75e7abeeaaa13696ab4067f0675e8be5bf3c93018b28a9d3fc4e706
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress installations. The heuristic 'ML_NYX_PDF_MALICIOUS' and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, suggests a lure related to exam answers, aligning with phishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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://crysiq.ru/uplcv?utm_term=exam+booster+preliminary+answers+pdf PDF link annotation
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/ab7a6e54b4feb35558026eb858b659aa/76253253886.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/39788227086.pdfIn PDF document text
    • https://peterdegendt.be/file/35171868802.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/84ftq40823cscbmio0uutpepkg/26065594774.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/390f63a9c499819b95a257856ab36c22/48172177703.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/62800055474.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/9r1cvio7kn94r1i1pq9joqadt5/82923092764.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/36983747013.pdfIn PDF document text
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/5d5975816c11eee0b9e2de4195719574/xufusuvumimabezisekeki.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb9179377a2---sufajizabatosu.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/16083bdc1949fc---7194267189.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/80dosasirnc86qaun6fta7q83g/zopijufuxibinilikive.pdfIn PDF document text
    • https://bringem.de/wp-content/plugins/super-forms/uploads/php/files/561366bb4c96b0a81db9e98e7f8ecddc/jikab.pdfIn PDF document text
    • http://upbfassadenbau.com/upload/file/tobubeb.pdfIn PDF document text
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b6ad2a295ad---78814171941.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001a86a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A86A 5548 bytes
SHA-256: 118e985e2855073736133068f40da4aa6938077a2256419b92ee24111db3bc11
font_01_sfnt_off0001bb46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BB46 12552 bytes
SHA-256: a5dea5a497f3557afc4580bc408cb3a223da4f70c4d0e1e4278aba057acb0b63