Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf81bdb32b617750…

MALICIOUS

PDF

76.0 KB Created: 2021-09-22 11:45:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: afbeb56bb10f1bb8d025efa8a0ba3226 SHA-1: 4f66248a7666f60790c4ec928ceb2ffed82366c3 SHA-256: bf81bdb32b61775068f29a0d3dd784b0500e0704743a93735062043aea95722c
134 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The ML classifier and ClamAV detection strongly indicate malicious intent. The numerous external URIs, many pointing to potentially disposable domains, suggest a link farm or phishing infrastructure designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9919

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
  • 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://unionnutritech.com/upload/files/55085109928.pdf In PDF document text
    • https://butchercurnow.com/img/shop/contents/45755856366.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/tibalawitevodog.pdfIn PDF document text
    • https://vitanov.rs/files/53433754293.pdfIn PDF document text
    • http://solarexperten.ch/fckeditor/editor/images/file/90791990389.pdfIn PDF document text
    • http://bocghedanang.com/media/ftp/file/pazenitosiruxorij.pdfIn PDF document text
    • http://kerekesvillszer.hu/UserFiles/file/52430391186.pdfIn PDF document text
    • http://web5gstore.com/Files/files/dajelep.pdfIn PDF document text
    • http://mnwebdesign.dk/userfiles/file/29713264137.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/luxobenaxivavinamokoga.pdfIn PDF document text
    • http://fst-uinsu.net/userfiles/files/zipesozige.pdfIn PDF document text
    • http://tion.hu/upload/file/bolabevesamojivokilov.pdfIn PDF document text
    • http://jtravel.clickis.kr/FileData/ckfinder/files/20210913_4B6CF2643BCCC1A3.pdfIn PDF document text
    • http://novelinternationalschool.com/ckfinder/userfiles/files/64065346280.pdfIn PDF document text
    • http://sro52.ru/uploads/files/nuxixebijo.pdfIn PDF document text
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d4fd954512---fisoxefevafu.pdfIn PDF document text
    • https://oncallanatomist.com/ckfinder/userfiles/files/duralubovugotigubukeni.pdfIn PDF document text
    • http://ux02.wadhost.com/js/ckfinder/userfiles/files/91910772687.pdfIn PDF document text
    • http://royalleasingny.com/admin/images/file/98258635600.pdfIn PDF document text
    • https://al-wesam.com/userfiles/files/69809862814.pdfIn PDF document text
    • https://diphong.com/uploads/85704926751.pdfIn PDF document text
    • http://ad.ditroinfotech.com/laportal/ckeditor-ckfinder-integration/uploads/files/75814368763.pdfIn PDF document text
    • https://dailyiat.com/html_upload/file/robajovepom.pdfIn PDF document text
    • https://frutalmente.pt/site/upload/file/38705519090.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=student+solutions+manual+to+accompany+modern+physical+organic+chemistry+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b9ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB9CE 1948 bytes
SHA-256: b033f7fcbcd390b2cb396fbb5f03ef01f7ca9afc151f9d9df21604321f961cfa
font_01_sfnt_off0000c2d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2D2 11356 bytes
SHA-256: b1f6e6a8dd5fe810e5b9df6b75166d2ff11527e085ffba19ddce2e821d0f00fb
font_02_sfnt_off0000dd34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD34 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off0000f546.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF546 16844 bytes
SHA-256: 3ac08445c725198ced939af59079e399997b5905d6f10d7e168ddfd7a6fba49f