Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b1c8dddc5bfbecc…

MALICIOUS

PDF

80.8 KB Created: 2021-09-10 23:47:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3afd8f265b85e357e598932785c1b7f3 SHA-1: e40598fe7dc47d7dfca188b33d3adae0fb6e7028 SHA-256: 4b1c8dddc5bfbecca72f6409696ac31e75490777892e9d7a8154fad8a40d0740
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with multiple URLs pointing to potentially compromised WordPress sites and disposable hosting. The embedded URLs and the nature of the link farm suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://1mosref.ru/ckfinder/userfiles/files/35286296716.pdf In PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133bf5d5335b---93494183711.pdfIn PDF document text
    • https://damsindia.org/admin/uploads/file/73678945541.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/tigozufazago.pdfIn PDF document text
    • http://budapesticukraszdak.hu/userfiles/files/xodez.pdfIn PDF document text
    • http://rkmaster.ru/uploads/files/32878364319.pdfIn PDF document text
    • https://fotojursa.cz/userfiles/file/1639322744.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/rizifuvejeresozejawepula.pdfIn PDF document text
    • http://lawfirm.vn/MINH/user_files/file/zizevajovumeveval.pdfIn PDF document text
    • http://m-s-g.ru/userfiles/files/zuxeguwelipapofofive.pdfIn PDF document text
    • http://soskuwait.com/outscapes/admin/ckeditor/uploads/ck/files/2460161691.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16135314be5b50---21018880106.pdfIn PDF document text
    • http://naitikfashions.com/ckfinder/userfiles/files/muzokudasododexotabimuvof.pdfIn PDF document text
    • http://www.ville-dammarie.com/ckfinder/userfiles/files/62830489093.pdfIn PDF document text
    • http://phonphangschool.com/upload/files/tugiragekewatino.pdfIn PDF document text
    • http://tubietelbar.hu/uploadfile/72305856631.pdfIn PDF document text
    • https://hssanesteban.cl/files/datinakutagozuxotonefed.pdfIn PDF document text
    • http://arredamenticucinesiciliane.it/userfiles/files/meragizil.pdfIn PDF document text
    • http://jeykrishnaclub.com/images/file/53089826250.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/d238b0fece9ed8b253335ddc51b0f560/mazugufum.pdfIn PDF document text
    • http://nature-revive.org/files/file/kedowupupumosutob.pdfIn PDF document text
    • http://meyanko.com/userfiles/file///xefefirolixoxat.pdfIn PDF document text
    • https://abzesolar.com/uploads/files/98726299999.pdfIn PDF document text
    • https://wendi101.com/userfiles/file/lilafesoz.pdfIn PDF document text
    • http://retco.ge/ckfinder/userfiles/files/3727784702.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=jak+odinstalowa%C4%87+aktualizacj%C4%99+androidaPDF 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_off0000d3f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC02 18036 bytes
SHA-256: 788fe0d8d5e5ef6d98c5289341b4e2ace55fe897b8a918a4c52355076c38c4be
font_02_sfnt_off0001197c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1197C 11036 bytes
SHA-256: f46970fe1620e7dae5dcb79ed9fec3a04093557ebb2ed30214866e422bbde644