Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb96e2e8aa424194…

MALICIOUS

PDF

69.6 KB Created: 2021-09-24 12:22:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 20c729b979f530e69df743b18e8bee45 SHA-1: 8b391e5611639f06af55ed61c27e1e76adc3e601 SHA-256: cb96e2e8aa42419436616542ea4ab2561a08db613c7b89307a2db968d5a89233
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for delivering malicious payloads. The PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicate that the document is designed to host or link to malicious content on compromised websites or disposable domains. The embedded JavaScript likely serves to redirect the user to one of these external sites, potentially for phishing or further malware download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • 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.
  • 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://latework.cz/soubory/50848977843.pdf In PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/92349526209.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612f99445c1f5---xarozevinixiwisoveb.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/1nijl4qlrau4stn7h4s8aqpau0/manawodogizefagaf.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/rewulobebovab.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/81901575101.pdfIn PDF document text
    • http://friend5190.xyz/js/ckfinder/userfiles/files/lofepiledonozaxe.pdfIn PDF document text
    • https://9ja-bet.com/userfiles/file/kegozuxufosi.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1613ebb8fcca1f---riwuwalumamuwovufa.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/ddd7f1dc950adb8442a2e25fc1689edb/92386447696.pdfIn PDF document text
    • http://labuchedeberce.fr/userfiles/file/wavorexazid.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134da531613b---48285121557.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/47125547287.pdfIn PDF document text
    • https://vnmmalta.com/userfiles/file/bulosilazovumixumodas.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/24099924851.pdfIn PDF document text
    • https://chsins.tw/uploads/files/202109051022434604.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=convert+android+emoji+to+iphonePDF 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_off0000af23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF23 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c735.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC735 16444 bytes
SHA-256: e8dcc98c00cc015b1d95e1584629957004b9d79588559328322beaed1bb5a2f9
font_02_sfnt_off0000f142.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF142 10672 bytes
SHA-256: 7a9791ca53e1e9fe1a1d1dc1685df000a1a005dd256cef0e4c37757e465d2c1e