Malicious PDF — malware analysis report

Static analysis result for SHA-256 d471ae03883b3ea4…

MALICIOUS

PDF

106.8 KB Created: 2021-09-14 12:35:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 8f8267d7033ec22ceeb98b62f9cbdb20 SHA-1: 61762254e58d6a387a7fb7ab084467345af6b244 SHA-256: d471ae03883b3ea417248a4a02181bddd41caf7b86ec67438b0063dbf53da541
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with a high-confidence ML score. Heuristics indicate it functions as a link farm, directing users to numerous distinct, potentially disposable domains. The embedded URLs and the PDF structure suggest an attempt to obscure the true malicious intent, likely leading to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9909

Heuristics 5

  • 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.
  • 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://www.waetsukai.jp/system/ckfinder/userfiles/files/24810831470.pdf In PDF document text
    • http://sport-zavora.cz/data/file/kubodifenonetebuj.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/80176566979.pdfIn PDF document text
    • https://apteka-wratislavia.pl/halatecza/userfiles/file/povuxizaloge.pdfIn PDF document text
    • http://www.allatpatikapecs.hu/images/file/51925928950.pdfIn PDF document text
    • http://shoreluxurylimos.com/userfiles/files/56225222796.pdfIn PDF document text
    • http://pomelieagency.com/userfiles/files/52439613646.pdfIn PDF document text
    • http://verduciautodemolizioni.it/userfiles/file/8188963940.pdfIn PDF document text
    • http://52963566.com/upload/file/202109041250356613.pdfIn PDF document text
    • http://szentimresiklos.hu/upload/file/6026259577.pdfIn PDF document text
    • http://greenmodels.ru/uploads/files/61171194443.pdfIn PDF document text
    • http://tid.vn/upload/files/41540053099.pdfIn PDF document text
    • http://solemarservizi.it/userfiles/files/varuwinekoxej.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/51907001114.pdfIn PDF document text
    • http://sun-dr.com/uploads/files/202109132012172115.pdfIn PDF document text
    • http://sb-78.ru/files/file/kejeze.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/sirexi.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/21188468338.pdfIn PDF document text
    • http://prokoncept.hu/admin/blogfck/image/file/92799589083.pdfIn PDF document text
    • http://tradeweb.es/userfiles/file/gazemos.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/kexipiwuxatodidatigu.pdfIn PDF document text
    • http://viethanit.vn/hinhanh/file/47106191422.pdfIn PDF document text
    • http://sandlnae.com/data/editor/file/64507673126.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=roblox+song+sheetsPDF 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_off000125fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125FE 19472 bytes
SHA-256: 036098ff95cb0664c7330332f68ea6d434edde1e68dd656195c1d0584fb2b439
font_01_sfnt_off00015879.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15879 10320 bytes
SHA-256: 5be28af2d4b52ff956cc3004e8a923dd809c269dbe5451ab29992f43652341f8
font_02_sfnt_off00016fc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16FC3 16132 bytes
SHA-256: 071bac7a3a90310621307d68123817e30fba7c89f9e5021c4391eb43bd8b9137
font_03_sfnt_off0001853a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1853A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1