Malicious PDF — malware analysis report

Static analysis result for SHA-256 51384a2e0c6a5fe0…

MALICIOUS

PDF

74.3 KB Created: 2021-09-24 07:22:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fb48a78d97d3fdba4c0440be77a08213 SHA-1: bafab171bed4b4ffb5307176b63064b488a58c6a SHA-256: 51384a2e0c6a5fe063d227f5ff383c7e818ed520ced7acfc0a9b26c0c6b6ad08
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier with high confidence. It contains a large number of embedded URLs pointing to disposable domains, indicating a link farm or phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically calls out the use of disposable hosting and redirector URLs, suggesting an attempt to distribute malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://smidgel.ru/uplcv?utm_term=king%27s+avatar+english+sub PDF link annotation
    • http://mtsskzy.com/userfiles/file/23590698153.pdfIn PDF document text
    • http://sanxuatbanthinghiem.org/app/webroot/uploads/files/10187497334.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/25451588384.pdfIn PDF document text
    • http://fobas.cz/userfiles/file/rebegomezo.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/ritekobofeduxoniravugap.pdfIn PDF document text
    • http://antitumor.org/filespath/files/20210915225854.pdfIn PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/somozasopokaram.pdfIn PDF document text
    • http://mrspk.com/ckfinder/userfiles/files/jubodidarudomodelesoraju.pdfIn PDF document text
    • http://yourmoneyyourbank.com/uploads/File/78263842467.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/vadiwumasox.pdfIn PDF document text
    • http://kimandyoo.com/userfiles/file/tedotevuzikelerefuwe.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/161382e1d0f89d---39522074878.pdfIn PDF document text
    • https://wintechindia.in/ckfinder/userfiles/files/66964270492.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/57601385420.pdfIn PDF document text
    • http://talcmanagement.com/uploaded_files/userfiles/files/42814075217.pdfIn PDF document text
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f4ab0b483---27092632091.pdfIn PDF document text
    • http://moscowballet.ru/userfiles/file/vidonekulumikonedu.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/64003500594.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/kumilibonomug.pdfIn PDF document text
    • http://kxxbs.com/uploadfiles/file/a/xinizoka.pdfIn PDF document text
    • https://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210906061429.pdfIn PDF document text
    • http://araratmebel.ru/img/file/83257114591.pdfIn PDF document text
    • http://aligokdemir.com/resimler/files/74610908176.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_off0000bf05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF05 10596 bytes
SHA-256: 2e229713a834baf083a8ee02fd0964cfde34ddec069f6ac7e8b3431bb509cec5
font_01_sfnt_off0000d72c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD72C 17328 bytes
SHA-256: c7db10a0659365af75ba3fe9438441586be5d19b97f4241ff0f24eb07a2b6d5a
font_02_sfnt_off00010368.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10368 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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