Malicious PDF — malware analysis report

Static analysis result for SHA-256 8188209054610a5f…

MALICIOUS

PDF

69.0 KB Created: 2021-09-27 00:59:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2a9fb01218e52f6d5c8534756799f792 SHA-1: dcd51a4fa5a84dfbe218bd7e6ae15ccc9a6fd217 SHA-256: 8188209054610a5f61417c5b880c2d0236295d2a42590ee010ba37a36ac600ff
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The PDF's structure and embedded URLs suggest it is designed to redirect users to malicious websites, likely for phishing or to download further malware. No scripts were extracted, but the overall pattern is consistent with a malicious PDF used for initial access.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://queure.ru/uplcv?utm_term=digital+notebook+goodnotes+free PDF link annotation
    • https://xyoaa.org/sites/default/files/files/39002402399.pdfIn PDF document text
    • http://olgapolyakova.com/files/files/wesafidivirawem.pdfIn PDF document text
    • https://nayyaralidada.net/alpha/ckfinder/userfiles/files/dozosukojewogimemim.pdfIn PDF document text
    • http://tenis-klubmoj.si/uporabnik/file/4332629491.pdfIn PDF document text
    • http://longchimvac.net/app/webroot/uploads/files/58469955053.pdfIn PDF document text
    • http://huspanda.com/data/ckfinder/files/gikavenuwufa.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/pidelolexexepuvaliver.pdfIn PDF document text
    • https://marathonblainville.com/userfiles/files/59883878712.pdfIn PDF document text
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/86498967749.pdfIn PDF document text
    • https://asiahealthcaredentalcentre.com/ckfinder/userfiles/files/rumoxupoj.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/36743736311.pdfIn PDF document text
    • https://sagarexpress.com/userfiles/file/72672149076.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/nibusumonavunorax.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/fesugudewizelofax.pdfIn PDF document text
    • http://www.siposferenc.hu/html/21629171246.pdfIn PDF document text
    • https://dreptultau.hotnews.md/upload/userfiles/files/9233580538.pdfIn PDF document text
    • https://dreamscapes.ca/dream_scapes/userfiles/files/namanedizusonidujewifa.pdfIn PDF document text
    • http://parkergeneralcontractors.net/userfiles/file/83968902623.pdfIn PDF document text
    • http://vako.vn/app/webroot/uploads/files/mubamidajug.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/sexezito.pdfIn PDF document text
    • http://tw-echen.com/uploads/files/202109200902468917.pdfIn PDF document text
    • https://mailing.crpm.ch/ck/ckfinder/userfiles/files/28073880705.pdfIn PDF document text
    • https://g4m3s-4p1-12s1.com/contents/files/leromamekozutorenededa.pdfIn PDF document text
    • http://ganteltechnology.com/system/userfiles/file/fafesewanete.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/161302e83379e2---rawuxisidap.pdfIn PDF document text
    • 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_off0000b026.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB026 14808 bytes
SHA-256: 56a109f79f7c8e82d6f4b910e4accccf2d06d271c86aa69f6d85f2a0eb0f83d5
font_01_sfnt_off0000d583.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD583 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ed9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED9A 10760 bytes
SHA-256: c9e8d8fab5b6d05bc1d99f34e22a072897381c6e8a3410edb78ddd060625f57e