Malicious PDF — malware analysis report

Static analysis result for SHA-256 23e1f629589aef3c…

MALICIOUS

PDF

81.6 KB Created: 2021-09-16 01:35:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 963fe7b0870c3f5ee9e7283bef9903d8 SHA-1: 3d8f0ac9688c136905b712d81d873730ee877533 SHA-256: 23e1f629589aef3c48a34b614a3275abfe5370c20fff400de56d3d142738950d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. The PDF contains numerous embedded URLs pointing to a link farm, suggesting an attempt at SEO poisoning or distributing further malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 https://dortmundpools.com/contents/files/wediravapidusakuroxamiro.pdf In PDF document text
    • http://vhz.cz/user-files/46277366519.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/28of3fmsehl6jt0k6big97fhjl/mawefuzowifilat.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/vitakok.pdfIn PDF document text
    • https://2winit.com/Files/files/xodikotufomozijamokakodox.pdfIn PDF document text
    • http://marcobernini.it/userfiles/files/75736215573.pdfIn PDF document text
    • http://inphuduong.vn/upload/files/33635051865.pdfIn PDF document text
    • https://www.orthovision-lublin.pl/ckfinder/userfiles/files/jubudononavesojutumi.pdfIn PDF document text
    • http://color-gateway.com/userfiles/file/58629487418.pdfIn PDF document text
    • https://aymfly.com/aym_image/files/46750490849.pdfIn PDF document text
    • https://xn----7sbeo1acdy3adh.xn--p1ai/userfiles/file/firezisopuw.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/wadimipidegobariwediw.pdfIn PDF document text
    • https://majubesar.org/contents/files/27169714784.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/gakasapodimonokowof.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/92208783955.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/komenusiwujeribanisafi.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb717039d9---4363763829.pdfIn PDF document text
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/bivibomuwarinotixipur.pdfIn PDF document text
    • https://detskeihriska.eu/ckfinder/userfiles/files/76187231988.pdfIn PDF document text
    • http://delta-serwis.pl/pliki/wixeg.pdfIn PDF document text
    • https://yifff.se/userfiles/file/tabevitefak.pdfIn PDF document text
    • http://kcpsystem.com/userData/board/file/kutezabom.pdfIn PDF document text
    • http://asvpp.fr/pdf/veritejeliri.pdfIn PDF document text
    • http://zovsh.com/Uploadfiles/files/88353199484.pdfIn PDF document text
    • http://blgjad.com/upload/files/74499850704.pdfIn PDF document text
    • http://sergeisurzhin.ru/ckfinder/userfiles/files/53304611968.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=windows+7+iso+for+limboPDF 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_off0000dd5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD5B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f56d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF56D 17100 bytes
SHA-256: 71c1aa9ad99e35cf82423b781e53bbda949887e702535f1340c07ab7bb5b2f8a
font_02_sfnt_off00012186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12186 10392 bytes
SHA-256: 96c047e8d58ee87b0671db9e24450093670459ebc7c5d8eaef68240cfd341a5f