Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f7e118889785ee…

MALICIOUS

PDF

79.8 KB Created: 2021-09-18 23:31:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 14810a887f6ec5c9280aecfee3c7b9c2 SHA-1: a0d003107f378a379698fa71ee6c121d5c4c9b7e SHA-256: 83f7e118889785ee69e51777f88a142ffb6c86c4c43d54b79dddf7231b803c1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or other potentially malicious hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malware. The document body is heavily obfuscated and unreadable, providing no direct user-facing content, but the heuristics confirm a link farm strategy.

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
  • 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://urologasdainys.lt/userfiles/file/likobo.pdf In PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16136a1ab87c86---jiripopunug.pdfIn PDF document text
    • http://kerama.altrodesign.eu/ckfinder/userfiles/files/56020155680.pdfIn PDF document text
    • http://bagodilovaspark.hu/userfiles/file/71962137162.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613d566344737---9248301115.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161390136168f2---vumizaberetut.pdfIn PDF document text
    • https://lombardpruszkow.pl/local/userfiles/file/korobozodow.pdfIn PDF document text
    • http://c-amc.com/upload/files/zonadetiritopajubisoluko.pdfIn PDF document text
    • http://seoaudytor.pl/userfiles/file/56798957437.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/fc1790db2706c929dd927eebc79d6cc8/fujuzasolosowofo.pdfIn PDF document text
    • http://sushiosushi.com/uploads/files/tebopalexenuzenajomito.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/nakuvikiruraj.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138aa60ef6b2---16014049729.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/86869923206.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/6f91235a1b826d0f5bb5b57baa095d93/63820222683.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/75645483539.pdfIn PDF document text
    • http://artvideo74.ru/upfiles/files/56437144511.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161320ae82cc68---69265366534.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f40c490d28---27985392192.pdfIn PDF document text
    • http://yuli-china.ru/d/files/galeritewisiwufomopolebal.pdfIn PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/8665434058.pdfIn PDF document text
    • http://ensky-chemical.com/upload/files/91271799915.pdfIn PDF document text
    • https://roshnaai.com/ckfinder/userfiles/files/97697844087.pdfIn PDF document text
    • https://10glazsikeyrosa.ru/file/47589517115.pdfIn PDF document text
    • http://3mfa.com/images/editor/files/tomitakek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=2017+gtr+for+salePDF 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_off0000ce8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE8A 19612 bytes
SHA-256: fae1cf6c871694c5d8b03d7530bea13691ae90478c1e26a81cdb2003ceef7a79
font_01_sfnt_off000101b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C8 10440 bytes
SHA-256: ad866a985f48553c15e176f455c10a61336f52b0eff2beb08bbf8a5996ed4ae3