Malicious PDF — malware analysis report

Static analysis result for SHA-256 56999d69ac5afcc3…

MALICIOUS

PDF

102.5 KB Created: 2021-09-12 21:48:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 1cefb560481fbd9bd9bf9dfcce3d8d7a SHA-1: a31ed0f338a5d53c20bc799137a0839dbac0605f SHA-256: 56999d69ac5afcc3d7c9d443c7e5141996227268da699913523bef53a5748447
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. It contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms, suggesting a phishing or malware distribution scheme. The PDF structure itself is also flagged for containing duplicate objects, which can be used for obfuscation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://z-him.ru/userfiles/file/zugozitolirevuludituve.pdf In PDF document text
    • https://reformedgeneration.com/userfiles/file/58482706147.pdfIn PDF document text
    • http://shangrilatheshow.com/ckfinder/userfiles/files/27365988586.pdfIn PDF document text
    • http://travelsi.ru/ckfinder/userfiles/files/xalerinufegi.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/bapovufaniti.pdfIn PDF document text
    • http://xn--80aer5aza.xn---42-5cdakyymnnb9ake1az.xn--p1ai/ckfinder/userfiles/files/walewa.pdfIn PDF document text
    • https://gotoko.com/cmsv2/upload/files/59279848499.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/zebaxemavewumero.pdfIn PDF document text
    • https://pinkrali.com/calisma2/files/uploads/74283868773.pdfIn PDF document text
    • http://bunny888.com/ckfinder/userfiles/files/netunapubevijid.pdfIn PDF document text
    • http://rybarict.cz/webpagebuilder/ckfinder/userfiles/files/4984140005.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/kodasurolapok.pdfIn PDF document text
    • http://www.pethouse.es/ckfinder/userfiles/files/nodenemulonikujadimuko.pdfIn PDF document text
    • http://donauwell.at/userfiles/file/8373872317.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/valibamasopekutuzaguda.pdfIn PDF document text
    • http://haohanlegend.com/Uploadfiles/files/44546688834.pdfIn PDF document text
    • http://kitpaisal.com/mypicture/file/duzamosusedabek.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/s80ovcauie27ru9i3pdf0o8dm6/19698106118.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///nojimibaneginimonajegib.pdfIn PDF document text
    • http://terremeraude.com/userfiles/file/23084037837.pdfIn PDF document text
    • http://01host.ru/userfiles/files/8898836547.pdfIn PDF document text
    • http://khachsansapa.vn/webroot/img/files/dukoxutovam.pdfIn PDF document text
    • http://netdepphunu.vn/images/userfiles/file/kimovu.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161358c50edaa5---50319211450.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=program+android+apps+in+pythonPDF 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_off000129b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129B0 10776 bytes
SHA-256: 7812bec05db2151c6deb489ed4330ed153365b4d4012cc910b916c0817219c21
font_01_sfnt_off0001421b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1421B 18868 bytes
SHA-256: a314b6cc637d002ac4fe336e08565f4069463e7f6ec33d468e76f4ccb2e7f1f6
font_02_sfnt_off00017419.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17419 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1