Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b3f25971ec02cfe…

MALICIOUS

PDF

82.2 KB Created: 2021-09-12 07:03:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7657a957f3eeeaaf39b4ed43c9536e86 SHA-1: cfbb6ead30f46f3687c34612edb739e30bcbe927 SHA-256: 5b3f25971ec02cfe384699c4fb60a130c09fa5614292b1e7b1c47a4bb2d5f015
126 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning model indicated a high probability of maliciousness. It contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically points to this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://synerhu.ru/uplcv?utm_term=screenshot+video+apk PDF link annotation
    • http://masan315.net/board/imagefile/file/76414764686.pdfIn PDF document text
    • http://www.cenlaenvironmental.com/siteuploads/editorimg/file/2556715856.pdfIn PDF document text
    • https://twinslock.com/locktactyuma/userfiles/file/tipegokana.pdfIn PDF document text
    • https://canoe.ro/Extras/ckfinder/userfiles/files/50081735403.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/c1273vihe0ienc9lpvglj15pmc/70578051806.pdfIn PDF document text
    • http://101balkon.ru/upload/files/bozivixotikudosor.pdfIn PDF document text
    • https://yaofangpeixun.com/upload/files/41354275472.pdfIn PDF document text
    • http://resortcrimea.com/ckfinder/userfiles/files/jarojavowu.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/kelixegojawomuperego.pdfIn PDF document text
    • https://promobryansk.ru/userfiles/files/guvanasabizerakefaxozuv.pdfIn PDF document text
    • http://cgl.lu/userfiles/files/44819064671.pdfIn PDF document text
    • http://csc020.com/userfiles/file/20210908175538_g9ld0r.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/barurinegoduruvat.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/nogolibija.pdfIn PDF document text
    • https://losaltos.com/wysiwygfiles/file/94434682242.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/lukepurukutamugetofanuk.pdfIn PDF document text
    • http://managhantasala.net/mailuserfiles/file/xafimujuwikag.pdfIn PDF document text
    • https://szallas-karpatalja.hu/upload/bikovuguzekes.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/kifokuvuven.pdfIn PDF document text
    • https://pisangmanis.com/contents/files/datinuxelerex.pdfIn PDF document text
    • https://valleyrentals.com/userfiles/file/laponuloroli.pdfIn PDF document text
    • https://matharu.ae/userfiles/file/xiligajizuzapogu.pdfIn PDF document text
    • http://sumisaedu.com/FileData/ckfinder/files/20210911_73EAD1BED05FABCA.pdfIn PDF document text
    • http://kamkmori.cz/ckfinder/userfiles/files/sawosebatus.pdfIn PDF document text
    • http://agrion.org/upload/fichier/70961777278.pdfIn PDF document text
    • https://eventpro-kontraktorpameran.com/uploaded/files/47615223516.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-9-2/20210902124854195508.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_off0000d808.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD808 10796 bytes
SHA-256: 10b6b6d41673f0c04b86c5da725a1aac6581fc36ae40b769702f743bb7c3bf45
font_01_sfnt_off0000f0e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108F3 19220 bytes
SHA-256: 89458dec024fad103abf0587357bbe28916176163715f33d344727a5ac3bc308