Malicious PDF — malware analysis report

Static analysis result for SHA-256 43b1fad1b35b035a…

MALICIOUS

PDF

72.7 KB Created: 2021-09-17 03:55:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 17f8d7b2ac6e17b8e5249c951e53a057 SHA-1: c8779bc6b99d1b73d6d9cc9e5172868f753051c7 SHA-256: 43b1fad1b35b035af396046f68a975d57376948b3fcb526d28dc8ba508e45e70
96 Risk Score

Malware Insights

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

The PDF file was flagged by an ML classifier as malicious and contains numerous embedded URLs, many pointing to compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the document functions as a link farm, likely to direct users to malicious content or for SEO manipulation. No scripts were extracted from this sample, limiting the ability to determine specific execution chains.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613735266e012---14046695441.pdf
    • http://cdn.eagle.mn/uploads/userfiles/files/tizizoropopegar.pdf
    • https://luiginoiobbi.com/userfiles/file/fomupuvukudarez.pdf
    • http://www.majbrno.cz/uploads/files/95777494820.pdf
    • http://madveras.com/ckfinder/userfiles/files/fusakak.pdf
    • http://hattrick-sports.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecb5ab0ffc---36478794936.pdf
    • http://spiregene.com/image/files/20210904_135014.pdf
    • https://medicabg.com/uploads/wysiwyg/files/38858247703.pdf
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161338e9d47cee---5035872303.pdf
    • https://specialgarden.ro/userfiles/file/jukaji.pdf
    • http://www.corazondelsol.es/ckfinder/userfiles/files/lamebusivakironulejim.pdf
    • https://shieldtech.cz/ckfinder/userfiles/files/35262376721.pdf
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/q1k5biaia3grg6uq22moi5fk5u/fafikonemisipakufudiniz.pdf
    • http://meruzhankhachatryan.com/app/webroot/files/file/4712206936.pdf
    • http://showpelec.com/data/file/20210907_060626_385.pdf
    • https://enerjimakine.com/tsrm1/img/userfiles/file/dijimomutejebos.pdf
    • https://akilanews.com/ckfinder/userfiles/files/finitarisexexepon.pdf
    • http://ipublicity.cz/data/file/jifozewarobowunobokizok.pdf
    • http://agataklimowska.pl/userfiles/file/91106168789.pdf
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16143d993ab91a---jesifewiju.pdf
    • http://3handseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc1dcd0e49---89178968501.pdf
    • http://pc580.cn/upload_fck/file/2021-9-4/20210904104920778564.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16136abb96590f---lafis.pdf
    • https://buzascsaba.hu/userFiles/file/3542090152.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/161340161bab34---35168367165.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=gaming+rom+redmi+note+7
    • 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_off0000bb57.bin
8d51a3f3e7f7d148f9931c727b5fa2f1b8bcc45bc4009ea142a36875dd91f243
pdf-font-stream PDF embedded font (sfnt) at offset 0xBB57 10468 bytes
font_01_sfnt_off0000d2eb.bin
48a0aec37f69a82637cf8e296fb75051cdb59f7f637a714467ff12d8e2b274a7
pdf-font-stream PDF embedded font (sfnt) at offset 0xD2EB 16516 bytes
font_02_sfnt_off0000fd71.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD71 16792 bytes