Malicious PDF — malware analysis report

Static analysis result for SHA-256 4dd2e11336ad2b8c…

MALICIOUS

PDF

78.5 KB Created: 2021-09-17 23:03:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1480ef5e81cc1c666c4bdddd382fe8a0 SHA-1: c338302995814455e1cc342c5b2fea3a0cf36a02 SHA-256: 4dd2e11336ad2b8c83719609375221a6dad46df4faa17a36292bac655a69cdb1
166 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to other PDF files on various domains, indicating it functions as a link farm. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest malicious intent, likely to distribute further malware or phishing content. The ML classifier and ClamAV detection further corroborate its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://drivingschool-brno.eu/files/38160667262.pdf In PDF document text
    • https://groupunsur4.com/contents/files/vinoforovajegijero.pdfIn PDF document text
    • https://paeonia.ch/userfiles/files/4443088798.pdfIn PDF document text
    • http://rustproofingottawa.com/userfiles/file/22413607337.pdfIn PDF document text
    • https://mediaskills.rs/files/gubapelivakutanawasijekam.pdfIn PDF document text
    • http://velapower.com/glwh/UploadFile/file/2021091401153873499.pdfIn PDF document text
    • https://habrit.tw/ckfinder/userfiles/files/madekepufimulikas.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/40949389621.pdfIn PDF document text
    • http://sreema.org/FCKeditor/file/vuviko.pdfIn PDF document text
    • http://www.globalnautique.nl/upload/files/dibevuzavimut.pdfIn PDF document text
    • http://terezszilvia.com/images/uploaded/file/14692516417.pdfIn PDF document text
    • http://humidorio.de/ckfinder/userfiles/files/57519113579.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a9bd67902e---dorixu.pdfIn PDF document text
    • http://rhoptik.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/44741958906.pdfIn PDF document text
    • https://horkolas-gatlas.hu/ufiles/file/15596360805.pdfIn PDF document text
    • http://maidichike.com/upload/files/79905610012.pdfIn PDF document text
    • http://ltpbetel.ro/userfiles/file/96142513704.pdfIn PDF document text
    • http://goldendoodlesofthesierranevadas.com/userfiles/file/1877342890.pdfIn PDF document text
    • http://cathugo-catamarans.de/res/wysiwyg/file/5541283769.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/tibififumotazavolibolix.pdfIn PDF document text
    • http://natalieshuff.com/uploads/file/15615300610.pdfIn PDF document text
    • http://ehoron21.mn/uploads/files/67031046368.pdfIn PDF document text
    • http://dataction.org/demo/dataction/media/275798104.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=rockstar+roblox+idPDF 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_off0000cb24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB24 18868 bytes
SHA-256: 139d3b95b6cce56677a2a30ef76fcfbaca1f218388220545842c259edfaae028
font_01_sfnt_off0000fd06.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD06 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001151d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1151D 10504 bytes
SHA-256: 0d8c7a4a833ff6d44ae7723d4f4850d4c5cd341d1a685359b5c2fb6f2e430f08