Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb0558c398df6635…

MALICIOUS

PDF

85.7 KB Created: 2021-10-21 16:34:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 23801dc3498cab26d7cc768476afd6f7 SHA-1: 467ed1fb40acb385f3a8c59b045dde2134d18236 SHA-256: bb0558c398df66350cea66b09856eb7281047c206a3a3463c9ba04cb67eff501
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, one of which is associated with a download lure. The presence of numerous external links and the ML/ClamAV detections strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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=second+conditional+reading+comprehension PDF link annotation
    • http://nincity.de/inline/file/gumegakufasi.pdfIn PDF document text
    • http://gianniarnaudo.com/userfiles/files/18558854861.pdfIn PDF document text
    • http://ilsungwarehouse.com/userData/ebizro_board/file/7517607413.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614c5f6ae8f3c---xugigawadeladitesafume.pdfIn PDF document text
    • https://indian-sped.szabgab.hu/fck_uploads/pdf/22910237978.pdfIn PDF document text
    • https://cliniquemyo.com/userfiles/file/xizuvep.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/jaxetepifogijowusipuki.pdfIn PDF document text
    • http://apmnir.ro/fckfiles/file/18672202923.pdfIn PDF document text
    • https://pensiuneavalentina.ro/app/webroot/file/pabakedemamotuxan.pdfIn PDF document text
    • http://greathorserider.com/ckfinder/userfiles/files/lefonesizazulebutifav.pdfIn PDF document text
    • http://bankerz.in/qpic/files/widogulopo.pdfIn PDF document text
    • http://ucinnovation.ru/admin/ckfinder/userfiles/files/70462671368.pdfIn PDF document text
    • http://rurisnet.org/images/file/95553222682.pdfIn PDF document text
    • http://elitk.ru/_files/suverobu.pdfIn PDF document text
    • http://bamboomfi.com/htdocs/cljr/data/files/tabomekagomimexekumil.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021101421491673499.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/17289215430.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/48320066141.pdfIn PDF document text
    • http://imbirimbir.ru/files/31128566244.pdfIn PDF document text
    • http://heninrealty.com/userfiles/files/napasopobotudano.pdfIn PDF document text
    • http://rwdwebwebdesign.com/img-aim/files/linekiwuwuxekijutomonosav.pdfIn PDF document text
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/juxogazijojikete.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/zurewixu.pdfIn PDF document text
    • http://modtre.com/fckeditor/editor/filemanager/img.php?file=file/68222324303.pdfIn PDF document text
    • http://tianlanip.com/filespath/files/20210926065518.pdfIn PDF document text
    • https://tuabogadoangel.com/wp-content/plugins/super-forms/uploads/php/files/d646b7c57ab129b61cd31812798ad30d/medulekatiwutuxamivo.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_off0000e541.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE541 19380 bytes
SHA-256: eb00d0586602d9c69d15bca49b6164261e30403996ef4a950f45b21def648021
font_01_sfnt_off000117ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012fd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FD1 11036 bytes
SHA-256: a8a106a61f54e47adc22320c441711281054495a2badff408d4ae90486fe791a