Malicious PDF — malware analysis report

Static analysis result for SHA-256 8efb59fad5599c00…

MALICIOUS

PDF

77.0 KB Created: 2021-09-30 10:24:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 276709228d5e71211adbf33c76bb3823 SHA-1: 1684d5b86ea3652c2bfefd55c9f737c0d8685606 SHA-256: 8efb59fad5599c00a290a5f42afb8444ba9b342c275436049f1bf1c8f3cd1070
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to a link farm hosted on disposable domains, suggesting a phishing or redirection attempt. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a strategy to obscure the final destination. While no scripts were explicitly extracted, the presence of external URIs and the link farm structure strongly suggest the PDF's purpose is to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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 http://malagi.pl/user-files/fck/file/risutabegotunubadovam.pdf In PDF document text
    • https://zahidnawaz.com/UploadedImages/image/775600367.pdfIn PDF document text
    • http://wonsakai.com/uploads/files/98419358465.pdfIn PDF document text
    • http://toitureetfacade.fr/data/Files/manapirikeno.pdfIn PDF document text
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/1d6a7d5fa4153896c4e549cb15778be4/jepabogenuxudipivo.pdfIn PDF document text
    • http://longchimvac.net/app/webroot/uploads/files/nodebuzevonuviru.pdfIn PDF document text
    • https://doosradashak.in/ci/userfiles/files/menajugezezedibevitozowip.pdfIn PDF document text
    • https://vietnaminsight.biz/ckfinder/userfiles/files/jetevunomijan.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/nivubalet.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/45814343201.pdfIn PDF document text
    • http://generaltubi.com/container/ckfiles/files/mujigik.pdfIn PDF document text
    • http://drcleancenter.com/uploads/files/202109281247552664.pdfIn PDF document text
    • http://studiovalentini.eu/userfiles/files/sosem.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/kuriguzitadujiwuzamo.pdfIn PDF document text
    • http://chieusangducphat.com/uploads/userfiles/file/xavarozuwoxuzumureta.pdfIn PDF document text
    • https://thefencedocumentary.com/adminfiles/file/69062763959.pdfIn PDF document text
    • https://christianschoch.ch/userfiles/file/82816012699.pdfIn PDF document text
    • https://r4binsh4h9-att.com/contents/files/41721556293.pdfIn PDF document text
    • http://crm333.com/documentos/file/menusof.pdfIn PDF document text
    • http://humidorio.de/ckfinder/userfiles/files/920445654.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16146a545b5921---jixixiwuselowuzutakevox.pdfIn PDF document text
    • http://etkenkalip.com/files/wixaxakas.pdfIn PDF document text
    • http://mindentudor.hu/userfiles/file/33285321092.pdfIn PDF document text
    • http://fst-uinsu.net/userfiles/files/12102701317.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=android+rooster+alarmPDF 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_off0000b419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB419 10392 bytes
SHA-256: 85660ccd71f4b63e0d08477e4d9c0207fb6a837e1fc98713c2282d0e3d8bf89f
font_01_sfnt_off0000cb98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB98 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e3aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AA 17580 bytes
SHA-256: d2a23615dc3b1760ec324e908bd8308f12d512ff408eb12281eb692d0e33fa10
font_03_sfnt_off0001101a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1101A 16232 bytes
SHA-256: 01cd0e4798e93fb086042d610f43ddeed7bf091af48aa863f5c4a4f61b651684