Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57f555e1d31cafc…

MALICIOUS

PDF

85.7 KB Created: 2021-09-09 23:13:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: e5b608d9c9fb599ec82d9d275db5385e SHA-1: 2baa35ee93a541275e1ce5c13f21c8699cd92648 SHA-256: a57f555e1d31cafc5ca4c2a0db2535903fba2e9280d4bfc661b31a4fe857f641
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM and the numerous unknown URLs suggest a phishing or spam campaign aiming to drive traffic to potentially malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://nangluongvada.com/uploads/files/62099440645.pdf In PDF document text
    • http://berallebags.com/UploadFiles/FCKeditor/20210903030530.pdfIn PDF document text
    • https://gonguyenkhoi.vn/upload/files/80079169103.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/202193354311090.pdfIn PDF document text
    • http://antonioruizabogados.es/userfiles/file/2548442490.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/16133efc1cc7e4---4536748381.pdfIn PDF document text
    • https://snqrsl.quebec/upload/editor/file/7513973162.pdfIn PDF document text
    • https://jungleflightchiangmai.jungle-flight.com/Uploads/files/tubumeraveguvukoku.pdfIn PDF document text
    • https://hondaotohaiphong.vn/upload/files/mipigegofesomak.pdfIn PDF document text
    • http://a-swiss.com/upload/userfiles/file/rimajiriku.pdfIn PDF document text
    • http://affordableadobe.com/ckfinder/userfiles/files/4292347932.pdfIn PDF document text
    • http://codienlanhminhquang.com/upload/files/nujutukalilafelanugarizox.pdfIn PDF document text
    • http://hiace-yoshikawa.com/js/upload/files/35892848122.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee1ec6f141---95200820296.pdfIn PDF document text
    • http://pharmabiosolutions.com/filespath/files/20210901073045.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/92752326051.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/13623952945.pdfIn PDF document text
    • http://eqletstalk.com/uploads/files/202109092129248599.pdfIn PDF document text
    • http://jingyilin.org/uploads/file/tuxaburidu.pdfIn PDF document text
    • http://chafewyuok.handysociality.com/upload/files/xodazuferovo.pdfIn PDF document text
    • http://patrickstaxi.fr/userfiles/file/54522839127.pdfIn PDF document text
    • https://idroilektriki.gr/files/file/gonunovijapokajoranufuneb.pdfIn PDF document text
    • http://hightopeducation.com/cms_uploaded/file/84245256839.pdfIn PDF document text
    • https://preprodpcb.com/userfiles/files/1615772593.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/xanegodobesidotupulot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=what+is+fetlife+app+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_off0000e73e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE73E 19568 bytes
SHA-256: 0aed55e226a7599c60c054ac388f1f497126819a3c81abbf2af64457ca0957d1
font_01_sfnt_off00011a11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A11 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013228.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13228 10216 bytes
SHA-256: 5a2ea7376727c568bee965b5166e6ba7261fb3ee5be9f17c351ef3d042018ff7