Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e4bb4988139eb7a…

MALICIOUS

PDF

83.1 KB Created: 2021-09-04 17:31:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: aa9d711572c4e86f8f58aec2e116d946 SHA-1: 9c767f8b9e94e4c511f3cfac91f06cb2128f6062 SHA-256: 4e4bb4988139eb7aab28e359df269f09840fc204f3fe905d79d84cc497d863a8
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute malicious files. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery via a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://medvor.ru/uplcv?utm_term=net+exam+2019+bengali+syllabus+pdf PDF link annotation
    • http://erbamedica.org/userfiles/files/nijakezupanadul.pdfIn PDF document text
    • http://morethancars.nl/uploads/edytor/file/vazuzofexene.pdfIn PDF document text
    • https://zweefvlieg.net/userfiles/file/3014643766.pdfIn PDF document text
    • http://jagodkaprzedszkole.pl/userfiles/file/65921619929.pdfIn PDF document text
    • https://biserica-izvorul-tamaduirii.ro/files/13613723410.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/ab1e3c436572286fe999b77078ea240d/48110712246.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/c74f7aba7cbc4fd9d95ed9c24a93387c/xufuwutomukukidonizute.pdfIn PDF document text
    • http://hilltop1976.com/clients/24685/File/vikavajudimolepepujono.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/62729904300.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/3983598331.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/e4652fc3c68635129118e4efc5663bb8/63316821245.pdfIn PDF document text
    • https://livredart.com/ckfinder/userfiles/files/19027717570.pdfIn PDF document text
    • https://igescanada.com/ckfinder/userfiles/files/jinegukixaruduralas.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/3d49245b7b2b2828a740309d8c3d4ca9/dubonijasazanogijipezewas.pdfIn PDF document text
    • http://morgancountyoh.com/userimages/28441367612.pdfIn PDF document text
    • http://acrclubinversores.com/files/galeria/files/55705491797.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/2021523153338.pdfIn PDF document text
    • http://autostyle-japan.com/js/upload/files/57548115870.pdfIn PDF document text
    • http://temple.mo/userfiles/file/32734165725.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/16072ff16400fe---49163236092.pdfIn PDF document text
    • https://www.electriclighting.com/wp-content/plugins/super-forms/uploads/php/files/f972cb61e1585f284ca736e3c58d6eaa/wikapetuj.pdfIn PDF document text
    • http://historico.uts.edu.co/portal/app/ckfinder/userfiles/files/gekofozomenotox.pdfIn PDF document text
    • http://soflcops.com/clients/83267/File/lolaxajagemediza.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://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_off0000dbd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBD3 18216 bytes
SHA-256: 5d3146143d98e2a6d30013f14f3eb8016501c18f6bb7a71fde1c6a8b9d692e13
font_01_sfnt_off00010b30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B30 11516 bytes
SHA-256: 1bd3dbe9a453f06590f1a19686f7ad7ab54c831e2447394446ee9d8b06995ff9
font_02_sfnt_off0001262e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1262E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1