Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a35e43b70a60557…

MALICIOUS

PDF

75.8 KB Created: 2021-09-17 22:55:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 035bb55db7d8978e0c5344c8d594ed71 SHA-1: 1d914a2911efeee5a306a7338bc9d1240e644f73 SHA-256: 8a35e43b70a605575a9b3b7057a1e0f2b6e85107f1701cf91de23381032d70e2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to a link farm, suggesting a phishing or SEO manipulation scheme. The PDF structure and embedded content, though obfuscated, are consistent with techniques used to deliver malicious payloads or redirect users to harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://winpoasia.com/ckfinder/userfiles/files/57391268439.pdf In PDF document text
    • http://szyoujin.com/UploadFile/file/20210907213158475.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc78892706---bulibotuzikipagenodanumar.pdfIn PDF document text
    • http://104408017.linker.tw/files/jewasokexugumosuvawik.pdfIn PDF document text
    • https://hebatkeren88.com/contents/files/62942778405.pdfIn PDF document text
    • https://ladachess.ru/userfiles/file/fexipofoloj.pdfIn PDF document text
    • http://www.fuchingrading.com/upload/file/nijosivibedezapil.pdfIn PDF document text
    • https://www.renouer-auxerre.com/ckfinder/userfiles/files/bekekomejufugexigonuwu.pdfIn PDF document text
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dapakifokativuxop.pdfIn PDF document text
    • http://www.texaco.bargiel.com.pl/ckfinder/userfiles/files/15829038160.pdfIn PDF document text
    • http://poultech.net/d/files/26884665244.pdfIn PDF document text
    • http://www.velkoobchod-man.eu/ckfinder/userfiles/files/13180109170.pdfIn PDF document text
    • http://teplospectr.ru/images/files/zikiwigololosalegu.pdfIn PDF document text
    • http://theheavent.com/userfiles/files/gizuw.pdfIn PDF document text
    • https://barcelonamedicalcenter.com/files/galeria/files/29264234157.pdfIn PDF document text
    • https://susta.vn/userfiles/file/49707273023.pdfIn PDF document text
    • http://kriosispl.com/cote_dor_import/admin/ckfinder/userfiles/files/18092926007.pdfIn PDF document text
    • https://arhstroi.by/uploads/files/funobawexojopop.pdfIn PDF document text
    • https://indiantiffin4me.com/nbloom/fckuploads/file/tobajuzowibobovuzibeja.pdfIn PDF document text
    • http://kondicionery-krasnogorsk.ru/upload_picture/file/xusoberotarorigabun.pdfIn PDF document text
    • http://ancient-theater.gr/media/file/naniwigedezus.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/nifapulutiru.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/vopigefazaxaloxakopepo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=motocross+android+gamePDF 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_off0000c62f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC62F 10660 bytes
SHA-256: 4199553a4c6aa4b5e45a9367635c74682688787da8505c2a848b9d013b89fdec
font_01_sfnt_off0000de65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f677.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF677 16936 bytes
SHA-256: 181f90707a5249a4fbf08ac7cda5768fff780511c465f57822015ce8b83157f1