Malicious PDF — malware analysis report

Static analysis result for SHA-256 673a4bfb08327845…

MALICIOUS

PDF

84.1 KB Created: 2021-09-12 23:50:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: dfb77681516c5c2ceb2fbc02e16e65c2 SHA-1: 3bbe5bf69b7e654d370631bfef6613a904a25f5e SHA-256: 673a4bfb08327845963ee0a47aea4dfd669ace6bcdd6fb5f8356523185d4a7ff
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URIs, including a link farm on disposable hosting, suggests the PDF is designed to redirect users to malicious websites. The primary attack pattern involves leveraging these links to potentially deliver further payloads or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://go-pxl.com/uploads/files/kebaxujijisiziwexeza.pdf In PDF document text
    • https://latgalesamatnieki.lv/files/file/82850923120.pdfIn PDF document text
    • http://xn--lv0az70cxar.tw/uploads/files/202109012328415619.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/161335e52bc390---59992309428.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/1792058474.pdfIn PDF document text
    • http://tsrmmessina.it/userfiles/files/24963361527.pdfIn PDF document text
    • https://cuatudongsaigon.net/uploads/files/97534655864.pdfIn PDF document text
    • https://kenkochaya.com/user_data/ckfinder/files/66722863269.pdfIn PDF document text
    • http://fitviewer.com/files/file/88837886248.pdfIn PDF document text
    • https://sanipacific.com/attachment/file/rikagirejusobokipomob.pdfIn PDF document text
    • http://goksirkrupskimlyn.pl/img/upload/files/tikobazev.pdfIn PDF document text
    • http://rlmlaw.com/images/edit_images/file/85048171927.pdfIn PDF document text
    • http://jpind.pl/userfiles/file/lexal.pdfIn PDF document text
    • http://doubles301.jp/files/ckeditor/files/40379623319.pdfIn PDF document text
    • http://nenorm.com/files/files/34141587494.pdfIn PDF document text
    • http://koreaseowon.com/ckupload/files/rapijak.pdfIn PDF document text
    • http://to-kajihan.net/js/upload/files/pivoxejesap.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/d599ee5f8c69ebaea36d61b6fc158201/69116615175.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109010417096010.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/93096087096.pdfIn PDF document text
    • http://elementsgogreen.com/userfiles/file/5751525996.pdfIn PDF document text
    • https://rux-thai.com/ckfinder/userfiles/files/lojeboxidibo.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/musadukibagagozul.pdfIn PDF document text
    • http://medtravel.pro/images/hand_uploaded/files/jepigujinibizasepivuzi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=enable+usb+file+transfer+android+broken+screenPDF 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_off0000e4c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fcda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDA 17572 bytes
SHA-256: 56cd89182925f482cfdf7e83a9fa68a0d7ebab9623c7e4d16c5af4c0b2cdba22
font_02_sfnt_off000129b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129B0 10784 bytes
SHA-256: 34235594efddc2e41cef82a1f0de266889d8d5ea9aabd489de793127eda1168a