Malicious PDF — malware analysis report

Static analysis result for SHA-256 33c164dcbb05deb7…

MALICIOUS

PDF

69.7 KB Created: 2021-05-24 11:06:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 7ffc4804138e77c6dfbb005a26bb44e0 SHA-1: bb84f59208ed18ba2556169f8038c083df58851a SHA-256: 33c164dcbb05deb7d86739a5b9685e40ccaf9e2ab98c297d7bbb8678ef4ff007
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 designed to direct users to various external websites, some hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a malicious document designed to exploit user curiosity or need for information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://huntic.ru/uplcv?utm_term=how+to+reset+rca+cambio+tablet+to+factory+settings PDF link annotation
    • https://www.chartsunlimited.com.ph/wp-content/plugins/formcraft/file-upload/server/content/files/160786288db9a6---80844219597.pdfIn PDF document text
    • http://www.aluvascientific.com/UserFiles/file/62959803380.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5a396cdb3---mugejanub.pdfIn PDF document text
    • https://englewoodgrassfarm.com/wp-content/plugins/super-forms/uploads/php/files/bbf723912f7aa5bf3ee9b9a8ecdc77c4/78814807137.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/3jf94jbom0rcttekseiltue9k5/refijoxavimum.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/8f746835aqu48tmfilakeusbt2/bobasomatibujoxetuforino.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd2e0256ce---78423682060.pdfIn PDF document text
    • http://www.vitrierbxl.be/wp-content/plugins/formcraft/file-upload/server/content/files/160812d163e863---fejoramokesoxarezenil.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/63634643144.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/lenojo.pdfIn PDF document text
    • http://assushop.com/userfiles/assushop.com/file/jajupiwinob.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/nomikm89q24814g3o183au9r6c/75381304992.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/64f99c7bbc632a51280fb80f8929e2ae/tepivativulipowesizapa.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/v0b86eee6djvrrptv6fho592a1/94290961800.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_off0000d2cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2CF 5496 bytes
SHA-256: 4f243428bb9fff11644a9ee5c7d1a15d83f925a52b9414a6ae31f350fb66134d
font_01_sfnt_off0000e585.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE585 10604 bytes
SHA-256: 88503b43b34838b2ea161536ac71188bcf28da6665e3ab5f9ff8ad26f1e38d7b