Malicious PDF — malware analysis report

Static analysis result for SHA-256 66a1735e22dfae99…

MALICIOUS

PDF

88.8 KB Created: 2021-08-16 00:13:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 14ff3f3682d424e0e75dc9ac1f57f6b5 SHA-1: 0de32fe9c4f320325c98f8cc133786f0fbcd31de SHA-256: 66a1735e22dfae99c14b7dfebcbbdeef3769927cf3044e42be4edc75a4b41940
96 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous external URLs, many of which point to compromised CMS upload directories. The ML classifier strongly indicates maliciousness. The primary attack pattern observed is the use of a link farm to direct users to potentially malicious content hosted on compromised websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://pharma-tools.eu/galeria/file/lonitilazefo.pdf In PDF document text
    • http://caryhigh1987.com/clients/41333/File/votak.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/puou0r6opq3jvj9iok15okbm74/mevonadazezemuzi.pdfIn PDF document text
    • http://maristaslardero.es/userfiles/file/rosademiwamut.pdfIn PDF document text
    • http://hoteldazegliotorino.com/userfiles/files/nowawozuganaririwe.pdfIn PDF document text
    • http://bakineshr.az/ckfinder/userfiles/files/10420724475.pdfIn PDF document text
    • http://bezpiecznamlodosc.org/files/file/23762622062.pdfIn PDF document text
    • http://apsencollege.org/test/fckeditor/file/7054984722.pdfIn PDF document text
    • http://cnkls.com/userfiles/file/1625468059.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a80eafa9e89---powasokoxoxe.pdfIn PDF document text
    • https://www.ojchamber.com/ckfinder/userfiles/files/lupozudojibinepa.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/ronorazegepixo.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/kilifirejuz.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/1binrhm2sj2f3junen02fhie35/lasenojelukuruluruses.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608cd33829290---wixizapiwak.pdfIn PDF document text
    • http://kennycojewelry.com/userfiles/files/202106/1624050420.pdfIn PDF document text
    • http://mexvp.com/ckfinder/userfiles/files/41532303260.pdfIn PDF document text
    • https://banderlogclub.ru/Files/file/23317309633.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16086d928ca653---jifufiz.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/6d7295087e8302c0de31533fa6db5eb1/81762830294.pdfIn PDF document text
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/59a6163cdbd06170e8290764138a4166/mugifiduneri.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/6ae222ee21141e8e4dbd3d15ddedbc7d/daroz.pdfIn PDF document text
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be48eb752bd---82732827855.pdfIn PDF document text
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb09d45987d---74770694701.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=basic+english+grammar+4th+edition+answer+keyPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off0000e3ed.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xE3ED 24164 bytes
SHA-256: 712b2f07d89fba9fc3edbefdce14fdd596279ed57e46b503757953466471a0de
font_00_sfnt_off0000cbdc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBDC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E83 11240 bytes
SHA-256: 85479e7ff2c7d42120ba9011ba5b60d6454ebbf0b95828eda8b2f8c587f76ed2
font_03_sfnt_off0001289d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1289D 17456 bytes
SHA-256: 1933fc6c3a7f3b2df98a6d52a17a798fd476b93df28fa98ba1a52ef881ce94dd