Malicious PDF — malware analysis report

Static analysis result for SHA-256 22b62f655be5ce27…

MALICIOUS

PDF

92.4 KB Created: 2021-07-24 16:23:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: aee619de2618b2cb787cdef8739f92a9 SHA-1: 02e7c748eb466518d015ecd953c8508d00a2fffa SHA-256: 22b62f655be5ce27d9851197e076d9f86e5edaa3687bcee429d0807d9ca30035
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to other PDF files hosted on various domains, many of which are identified as disposable or potentially compromised. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated, preventing a clear understanding of its direct user-facing content, but the link farm heuristic is definitive.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://hongshengfish.com/uploadfiles/2021052908362382708.pdf In PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/3377469543.pdfIn PDF document text
    • http://mobilni-kadernictvi.cz/files/file/42673988470.pdfIn PDF document text
    • https://ceral.pl/ceral/pliki/file/bifulolakanajasawetinul.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/324a40e811fa20de36620561046f846a/4638681675.pdfIn PDF document text
    • https://perfecthospital.org/FCKeditor/file/12580296721.pdfIn PDF document text
    • http://xn--h1acbpobggs.xn--p1ai/data/files/47700876357.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/33274395139.pdfIn PDF document text
    • http://at2apigroup3.com/contents//files/wivepisef.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/1bb5f99c9ab7209511d8242342c3b693/gizurivexoragufozoborago.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/160a40a9cabecb---56062548518.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/qi646i22u4jh08p49fk8aahe8t/52168787487.pdfIn PDF document text
    • http://cnkls.com/userfiles/file/1624958377.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/h1iub9ktvvu6f0hfcm3rfhp8d5/14321231817.pdfIn PDF document text
    • http://pitchdecor-construction.com/user_img/files/jejadariraveva.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c4ea92ed8f4---vipoxotobudopobirukaxifav.pdfIn PDF document text
    • http://inewbus.com/wp-content/plugins/super-forms/uploads/php/files/57gt2h1tvmurn63d3j97s4at93/pezubaserudoni.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c784eb7d1aa---62769256432.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/3368234104.pdfIn PDF document text
    • https://ozmutludokum.com/userfiles/file/tiwuxowamozu.pdfIn PDF document text
    • https://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072e5f4eec88---jodib.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/f212ca83b8ed1b7e2a59a3b4fd974fe8/78927802282.pdfIn PDF document text
    • http://cosmikkino.ru/sadm_files/fatapisejozuputeseregovoj.pdfIn PDF document text
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160fb09e0eba5d---zavasegitosugokep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=guitar+chord+chart+complete+pdfPDF 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_off000104d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104D5 17144 bytes
SHA-256: 84489776fe4caaa3f441811aff3b6afd38daaf789cf7e433154e7d4af4bac38d
font_01_sfnt_off0001310e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1310E 10752 bytes
SHA-256: 3fa51921ad267f7768fa67871a15efe6622f8c0e0e33f3b38b10aa9c69a1eea5
font_02_sfnt_off000149ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149CA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1