Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9686926b2daf238…

MALICIOUS

PDF

80.2 KB Created: 2021-10-06 08:50:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 2cbe36b5bdfb34703419ff37b3af9175 SHA-1: bf1753bbfcc1a12bdd45224e6f326f962b49980a SHA-256: f9686926b2daf238bd85da9cfb608cad77c671138341b0bec9415878624229ae
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to suspicious PDF files on disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further suggesting a non-legitimate purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://toyotacri.com/userfiles/files/xokodudexopozusujodosow.pdf In PDF document text
    • https://vietrocknet.org/app/webroot/img/files/49401492059.pdfIn PDF document text
    • http://hakasasi.id/userfiles/file/82313338193.pdfIn PDF document text
    • http://clerus.hu/files/file/19378878412.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/56cdd837e9870caa9570e46aa82473aa/wizuruziv.pdfIn PDF document text
    • http://tetraeng.it/userfiles/files/kuzujitozibaz.pdfIn PDF document text
    • http://nbc.com.vn/ckfinder/userfiles/files/gonimubafokiwaj.pdfIn PDF document text
    • https://bompentax.com/quangbasanpham/app/webroot/upload/image/files/gesisudezukexup.pdfIn PDF document text
    • http://arci-mp.fr/admin/File/58270942629.pdfIn PDF document text
    • http://otvorene-srdce.sk/userfiles/file/23599224296.pdfIn PDF document text
    • https://thinkglobalcompliance.com/ckfinder/userfiles/files/38925394724.pdfIn PDF document text
    • https://hopclickhospitality.com/scgtest/team-explore/uploads/files/62001153993.pdfIn PDF document text
    • http://roland-toys.eu/userfiles/file/risagilewanotaxijukunuza.pdfIn PDF document text
    • http://www.investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/29856178681.pdfIn PDF document text
    • http://clinicaveterinariacene.com/userfiles/files/kikamoloku.pdfIn PDF document text
    • http://bebsulmare.com/userfiles/files/nepujerejet.pdfIn PDF document text
    • https://nguyenhungstone.com/uploads/image/files/ridopawodipuxud.pdfIn PDF document text
    • https://himalayanthailand.com/image/upload/File/wuwijutaxusoduwixeluwiwa.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/57563117765.pdfIn PDF document text
    • https://petribax.com/userfiles/file/fomumibukim.pdfIn PDF document text
    • http://modnyi-buket.ru/uploads/files/sobumo.pdfIn PDF document text
    • http://ps-chiptuning.hu/userfiles/files/84913758761.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=private+equity+partnersPDF 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_off0000d31a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD31A 10504 bytes
SHA-256: b306c59e530bb4522d717e2d890d6353ccea3522a2626a83369483b6a331aae5
font_01_sfnt_off0000eb24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB24 18892 bytes
SHA-256: 7f9078d16bb6ceb9459e907a2181e5fbed42ef2f8043a9b496af72a2b2961a1e
font_02_sfnt_off00011bc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1