Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9b17b9fd2c3c38c…

MALICIOUS

PDF

69.9 KB Created: 2021-09-22 10:04:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ad1f569323761bd1a72801d7d7a11b54 SHA-1: ef21d3e35c078a7a4c2d0f6c7605ba6ff631c5af SHA-256: f9b17b9fd2c3c38ce780bd9d85d0c9ac4d06bb595ac9eea5183d96dacfab65dd
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a heuristic firing for a link farm, indicating it's designed to redirect users to multiple external URLs. The presence of numerous PDF files hosted on various domains suggests a coordinated effort for phishing or malware distribution. The ML classifier and ClamAV detection strongly support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://studio5r.com/userfiles/files/bogosera.pdf In PDF document text
    • http://findmecakes.com/userfiles/files/95424297825.pdfIn PDF document text
    • https://aldaserwis.pl/ckfinder/userfiles/files/letofetomipi.pdfIn PDF document text
    • http://cuahuyhoang.com/media/ftp/file/47296245785.pdfIn PDF document text
    • https://codefon.hu/js/ckfinder/userfiles/files/78506846519.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1614060e9cdd2d---21058597378.pdfIn PDF document text
    • https://pilot-nav.socksnbows.com/ckfinder/userfiles/files/xubur.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613d0bcd43631---xuvigakepibukilux.pdfIn PDF document text
    • https://driftwoodcc.com/userfiles/files/pipuxid.pdfIn PDF document text
    • http://studiobardinisrl.com/userfiles/files/vusekefubudedoba.pdfIn PDF document text
    • https://ezgoe.com/10005001208290177/ckfinder/userfiles/files/92632266926.pdfIn PDF document text
    • https://stpatswatertown.org/ckfinder/userfiles/files/1032290166.pdfIn PDF document text
    • https://cherrychile.cl/cherry/uploads/contenido/files/kafevuvawubon.pdfIn PDF document text
    • http://meskerjager.nl/media/files/12547483563.pdfIn PDF document text
    • http://medicare-darmstadt.de/bilder/UserImages/file/11161462178.pdfIn PDF document text
    • https://cleanenergy.mn/uploads/files/65525248308.pdfIn PDF document text
    • https://warungmimpishio.com/contents/files/fibavenikezudadum.pdfIn PDF document text
    • https://office-agglo-larochelle.fr/userfiles/file/73023249054.pdfIn PDF document text
    • http://av72-reklama.ru/userfiles/file/163158352540477bc2adceef4d2c90.pdfIn PDF document text
    • http://ana-jsc.com/upload/files/powidixolixumabuni.pdfIn PDF document text
    • https://hijaustabilo.com/contents/files/muregavibovibiza.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/wevuwerekixatufebibogibi.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/mutowetumajetijabog.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-9-4/20210904054938341219.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=hill+climb+racing+2+vip+apkPDF 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_off0000b48d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB48D 14792 bytes
SHA-256: fdf597d3889adda6cada034f34c90531cf8557959210658f8bf67f78f5f513ed
font_01_sfnt_off0000d98d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD98D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f1a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1A4 10608 bytes
SHA-256: a50ff38ef995eb7337a6c790780caef042ceb71749dfb42c7a9a9ec7eb0080bf