Malicious PDF — malware analysis report

Static analysis result for SHA-256 91efae319a7c6c23…

MALICIOUS

PDF

92.6 KB Created: 2021-03-11 03:35:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 3691c76d87086d0ed8147a5f3e753501 SHA-1: 2589ab980e25ca8fe000d10a96a416565349a8ff SHA-256: 91efae319a7c6c23cb05d2500b8ecb034210a1748a165a4472e2d96883d179bc
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, identified as a link farm for SEO purposes. Several heuristics indicate this is a malicious PDF, including ML classification and ClamAV detection. The embedded URLs, such as 'https://kuzutuzo.ru/123?utm_term=bass+dj+song++2017', are likely used to redirect users to malicious content or phishing sites. No scripts were extracted, but the structure suggests an attempt to manipulate search engine rankings or distribute malware via the numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://kuzutuzo.ru/123?utm_term=bass+dj+song++2017 PDF link annotation
    • https://cdn.sqhk.co/kajipazuto/diitffG/indoor_archery_tournament_rules.pdfIn PDF document text
    • https://cdn.sqhk.co/nojumuku/6ibMojh/build_more_cash_flow.pdfIn PDF document text
    • http://desajegurake.scienceontheweb.net/manulugizenataputike.pdfIn PDF document text
    • https://cdn.sqhk.co/nuditufu/ihjgH26/93136254552.pdfIn PDF document text
    • https://sufidubiziden.weebly.com/uploads/1/3/4/7/134732268/876c7c4df.pdfIn PDF document text
    • https://cdn.sqhk.co/bexefoboxevi/xNhg4V7/sipofilogutatatuvarevoni.pdfIn PDF document text
    • http://gemubanabugawa.mypressonline.com/fiwipifawugowatoga.pdfIn PDF document text
    • http://pifovabu.getenjoyment.net/53392684748.pdfIn PDF document text
    • https://mabobuloxulekev.weebly.com/uploads/1/3/4/6/134692970/volopudujodebekogi.pdfIn PDF document text
    • https://cdn.sqhk.co/dafisuwikib/Xhahagj/word_stacks_3921.pdfIn PDF document text
    • https://cdn.sqhk.co/niripakexad/Ojdgict/35913833337.pdfIn PDF document text
    • http://baderezu.scienceontheweb.net/wagarodotivujozotijesuke.pdfIn PDF document text
    • https://cdn.sqhk.co/zoluxoni/fWEI37E/mike_v_skateboard_party_pro.pdfIn PDF document text
    • https://cdn.sqhk.co/kososojog/SgeGLl2/t-_mobile_digits_app.pdfIn PDF document text
    • https://cdn.sqhk.co/wesuwajil/NeMhgjg/vosigopur.pdfIn PDF document text
    • https://cdn.sqhk.co/gixedomawa/harggjf/nufodopumejixipor.pdfIn PDF document text
    • https://fenitejum.weebly.com/uploads/1/3/2/3/132302819/8a8d008575e43e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fogokenum.onlinewebshop.net/18922531163.pdfIn PDF document text
    • http://ralirajuz.atwebpages.com/casio_gw-9400-1cr_review.pdfIn PDF document text
    • http://miganuvag.myartsonline.com/love_poems_pablo_neruda.pdfIn PDF document text
    • http://xobeminal.atwebpages.com/geretaduleti.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012fb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FB3 5396 bytes
SHA-256: 0968a75da85da50e468aaeef3ecba8328359e9339b7c9392038da2875838bc38
font_01_sfnt_off00014233.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14233 10212 bytes
SHA-256: 766a0944d641181e95ae27c96710e9315bb2f7cd2bb48842ff5040aaa820f2fa