Malicious PDF — malware analysis report

Static analysis result for SHA-256 81461cd5ab5f74da…

MALICIOUS

PDF

118.6 KB Created: 2021-06-18 23:53:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 94760fb2e4ab6dbf0fbbeec986a24e93 SHA-1: 9b61022c880acc99422a1ebbf708d8c92e4ad96e SHA-256: 81461cd5ab5f74daba6b1f52fa11561a32f9a38f8ff5e57f8f69d3a8f09e217d
156 Risk Score

Malware Insights

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

The PDF document contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution, by masquerading as a game walkthrough. No scripts were extracted, but the PDF structure and URL patterns are indicative of a malicious campaign.

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 https://lee-trading.tw/archive/upload/files/4454746791.pdf In PDF document text
    • https://alexandrapanayotou.com/web/images/static/file/93324891018.pdfIn PDF document text
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607a70c657b8c---8067929087.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/j7mqb52dp5af9i4vjee2qkgqkt/jejizezupiwud.pdfIn PDF document text
    • http://haohanlegend.com/Uploadfiles/files/kobagi.pdfIn PDF document text
    • https://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16085f1bc75f3b---91642389506.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/f8ac5be7f05ede43a79c0372e47aa942/dujoduvepebowuvegijo.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/5ocfeab0k3kv63j7muku4j1ap8/kowitona.pdfIn PDF document text
    • http://aggengr.com/uploads/CMS/file/39708949104.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/15922076179.pdfIn PDF document text
    • https://www.hotwaterfactory.com.au/wp-content/plugins/super-forms/uploads/php/files/7c63f61cf70dc1e3249437d50d149315/85494994546.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f223341a8b---65558304577.pdfIn PDF document text
    • https://bienenaktuell.com/sites/bienenaktuell.com/files/file/45739310978.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/160753369ddd18---35761552394.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609405bb00179---95068423999.pdfIn 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/~3/1KS0DP0cxss/uplcv?utm_term=marvel+lego+ps4+walkthroughPDF 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_off000192b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x192B3 5388 bytes
SHA-256: 9e8dd9384613dc2dc7599d23ba603b1ef7f343357ba4cbb87f53ae1b614b9e23
font_01_sfnt_off0001a52a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A52A 11216 bytes
SHA-256: c80e3b4a6184ad329e90a33247da5fcbb0a5c200a50ebadc3fa656d9536ff0a3