Malicious PDF — malware analysis report

Static analysis result for SHA-256 dcba7dc9f13d6056…

MALICIOUS

PDF

72.8 KB Created: 2021-09-26 07:05:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f12ff5d31931c6cf921f70e1f55df5af SHA-1: b243395e8e292b88fdce7123c206f7b8ae3b5b23 SHA-256: dcba7dc9f13d605631f7f88d419fab88b6a7aab048330550ca6c7208b4209331
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing campaign. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to redirect users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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.
  • 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://baoyi-chuck.com/ckfinder/userfiles/files/vafovoxukugukiboluwejen.pdf In PDF document text
    • http://merklink.nl/site/data/ws/files/13468309559.pdfIn PDF document text
    • http://yurisolomko.com/userfiles/file/36851571970.pdfIn PDF document text
    • http://easternhoteljeju.com/FileData/ckfinder/files/20210919_9D6C84E5C302BC5F.pdfIn PDF document text
    • https://idd.no/ckfinder/userfiles/files/84910394475.pdfIn PDF document text
    • https://mamotato.ro/userfiles/file/80835206837.pdfIn PDF document text
    • http://ride-on-earth.com/images/blog/file/vepebuv.pdfIn PDF document text
    • https://hyosung-gulf.com/uploads/file/79201345995.pdfIn PDF document text
    • http://faurau.com/luodan/images/userfiles/file/86704322593.pdfIn PDF document text
    • http://gyliver.ru/files/files/73996401493.pdfIn PDF document text
    • http://benevolo.it/userfiles/files/81172811868.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/49003832774.pdfIn PDF document text
    • https://mkserwis.pl/userfiles/file/17780275667.pdfIn PDF document text
    • http://www.sport-konyv.hu/userfiles/file/xasanikexuxaripivukugumom.pdfIn PDF document text
    • http://kwartetproforma.com/userfiles/file/47451456999.pdfIn PDF document text
    • http://nenorm.com/files/files/22339064711.pdfIn PDF document text
    • http://krzeptowski.pl/file/28718605976.pdfIn PDF document text
    • http://solemarservizi.it/userfiles/files/83362777473.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///48082324234.pdfIn PDF document text
    • https://fjordancv.info/wp-content/plugins/super-forms/uploads/php/files/0a7ebeffce3cb853e2c35df338a55eea/21536132164.pdfIn PDF document text
    • http://huonglonghotel.com/uploads/image/files/84769305316.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/62150777873.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16139ab7290dfb---47573080841.pdfIn PDF document text
    • http://gpba.ge/admin/ckeditor/ckfinder/userfiles/files/77377303869.pdfIn PDF document text
    • http://angelojrobles.com/admin_initial_test/userfiles/file/xumuvarokewepegalusisi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=how+do+i+add+contacts+to+my+phonePDF 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_off0000b51f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB51F 10824 bytes
SHA-256: 6e2aa301a5a08007756214ab86bdf7f4879c377e151c4871507f9818e54a3e85
font_01_sfnt_off0000cdf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDF1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE603 18460 bytes
SHA-256: 3c928ad966a907b4231284b7cdc0c968db30aa419368ad80ced516126b9c0d2f