Malicious PDF — malware analysis report

Static analysis result for SHA-256 735c97a23db0f8b8…

MALICIOUS

PDF

78.0 KB Created: 2021-09-07 04:05:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f8bac20101c60cbb5d22d8f2cc885ac SHA-1: 57dd1df20994a0ee9b758ecece1f01baccca8cf1 SHA-256: 735c97a23db0f8b804e46e0ce2d9410610f3bc05fea1743fde61712a6447c76b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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 https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/mpohvhfkfjinvpr2q105gsfr23/wuvizem.pdf
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/f5e6979bd57d61b42c829e22939e2fcf/tenizudeb.pdf
    • https://ctners.com/ckfinder/userfiles/files/40177534362.pdf
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/b06d90f62be1da82e0dab874368df9a2/zuwovizefavalelasozebuvul.pdf
    • http://quatangsongvan.com/hinhanh_fckeditor/file/45989484487.pdf
    • http://dokumsuzgec.com/userfiles/files/sikit.pdf
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1606dbfff2b165---14812513787.pdf
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/b7911b6855f64146369e9467c8639fa0/soxubuzavagerupi.pdf
    • http://pamat.ro/UserFiles/file/firogur.pdf
    • http://kondicionery-dolgoprudny.ru/upload_picture/file/molobigujoniwapem.pdf
    • http://thedewakohchang.com/image/upload/File/4380202210.pdf
    • https://llsindia.in/FCKeditor/file/japapagafupi.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160759c880a032---vezogililuxosama.pdf
    • http://praguetransfer.com/files/file/3778183623.pdf
    • https://akvaguru.hu/user/file/navusoxapavedopiboxi.pdf
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070027e1c789---juruw.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/c559b5854e4aab4006b08665b7ef6c19/joluzakejas.pdf
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/086b4fcd32f4ba5ec22d2a96c1d9f310/xijemodilemelenubizapu.pdf
    • http://ahchala.com/img/file/pabijararif.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/fd306613f18dd084faea96d528539da0/90221701083.pdf
    • https://hbfilm.ca/resimler/files/42028877613.pdf
    • http://xinghui.co/upload/ckimg/files/202108191217599152.pdf
    • https://prokoncept.hu/admin/blogfck/image/file/poperogujuze.pdf
    • http://isemya.by/modules/ariol/static/ariol/ckfinder/files/36929816720.pdf
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/d8657e99b45607714ae457cb7e27a302/13258712696.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=importancia+caracteristicas+y+estructura+de+los+estados+financieros+basicos+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb8a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB8A 16792 bytes
font_01_sfnt_off0000e39c.bin
82d1d6af93518bbda025bb23cab4018f40101ca79ec6ba67f33c1cf5220a1da4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE39C 16940 bytes
font_02_sfnt_off00010e19.bin
19965eccb6af74f94eca73c0a1b2ca253ba7542ee47e56ca2d68c674b33235f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E19 11088 bytes