Malicious PDF — malware analysis report

Static analysis result for SHA-256 b308159bbc36716f…

MALICIOUS

PDF

79.1 KB Created: 2021-09-23 13:34:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3b7b75d5f8e38ca99ecb40b02cd5a0cc SHA-1: 381d20159c3bcc221ce67b3d883db4c14061ea7d SHA-256: b308159bbc36716f67518e359d75e8c1b34d6e8d1be00d42f806d6d2fbe51fd7
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

This PDF was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. The heuristics indicate it functions as a phishing lure, specifically using invoice or payment-related language to trick the user. The document contains numerous embedded URLs, many of which point to suspicious PDF files, suggesting a link farm or redirection mechanism to deliver the malicious payload. No scripts were extracted, but the overall pattern points to a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 7

  • 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 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://klaaswester.nl/img/file/91264472854.pdf In PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f1ebbb3685.pdfIn PDF document text
    • http://hamkr.com/userData/board/file/rupijo.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/kizexonamatum.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/94391403090.pdfIn PDF document text
    • http://fukaofoods.tw/uploads/files/202109120936383537.pdfIn PDF document text
    • https://hagakure.by/upload/editor/files/97720138842.pdfIn PDF document text
    • https://iwanbim.com/userfiles/files/lenitemuzubitozoxuwagegot.pdfIn PDF document text
    • http://lesen-und-schenken.de/userfiles/files/futuzafarusa.pdfIn PDF document text
    • http://www.ecvbrass.ch/user/web/file/94945229679.pdfIn PDF document text
    • http://architettodrabeni.it/userfiles/files/dulalevo.pdfIn PDF document text
    • http://zhymwz.com/upfile/file/31851836139.pdfIn PDF document text
    • http://artgraf24.pl/userfiles/file/86683590569.pdfIn PDF document text
    • http://wx-bm.cn/upload/ckimg/files/202109101556208525.pdfIn PDF document text
    • http://kubkao-kubpla.com/userfiles/files/bijope.pdfIn PDF document text
    • http://satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/44487835898.pdfIn PDF document text
    • https://guclupin.com/calisma2/files/uploads/tuwoteve.pdfIn PDF document text
    • https://etonbio.com/newsLetters/images/file/75166801570.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/nofemuligimapidororim.pdfIn PDF document text
    • https://amrapalispot.com/userfiles/file/mowewejiva.pdfIn PDF document text
    • http://lexxyin.net/files/fckeditor/file/82504665580.pdfIn PDF document text
    • http://www.jucadent.es/ckfinder/userfiles/files/34189034456.pdfIn PDF document text
    • http://ruizhishengwu.com/uploadfiles/file/210632556895.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=facturacion+oxxo+pdfPDF 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d216.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD216 10444 bytes
SHA-256: 54055aaf2aa941a959401e0808aa5d8e280665d28946f38641d6f2f1fb800ffa
font_01_sfnt_off0000e9ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000101fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101FC 17576 bytes
SHA-256: 588c0d691a4eaf1062b75c364ecd5eaac9f94fe7cba7e11230b9ec05d304fe60