Malicious PDF — malware analysis report

Static analysis result for SHA-256 c337b50edbe1f504…

MALICIOUS

PDF

82.9 KB Created: 2021-09-23 23:01:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 1111d75aa97d9db8262b46dcca3c6c1d SHA-1: 1b3aaac5b0d7d5aa23301c9ec247c71facf414ef SHA-256: c337b50edbe1f5048858fcbbdf80e67785fd553f0e17885d5f8a31f09ff93992
156 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis point to a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://garglob.ru/uplcv?utm_term=refuse+to+choose+book+pdf PDF link annotation
    • http://www.aunay-sous-auneau.fr/ckfinder/userfiles/files/88507922358.pdfIn PDF document text
    • http://sun-tes.ru/files/file/2419758649.pdfIn PDF document text
    • http://www.fd.ntou.edu.tw/ckfinder/userfiles/files/migefatawifoxibeteru.pdfIn PDF document text
    • https://ciela13.leaddeehub.com/userfiles/files/wivojopo.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/q7ed1u8trep8q3dsb0q0vkn7k0/42867424048.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fed805ca4a---66484890314.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/60861148393.pdfIn PDF document text
    • https://zoldlepes.hu/userfiles/file/ribupanipo.pdfIn PDF document text
    • https://ktmcollege.org/public_html/userfiles/file/tarajelowaleku.pdfIn PDF document text
    • http://gesht.ru/admin/ckfinder/userfiles/files/vaxibom.pdfIn PDF document text
    • https://sharedsynergy.com/userfiles/file/52198917729.pdfIn PDF document text
    • http://parmalab.it/userfiles/files/farodexedilepebinakopufik.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/4adc66b1305e580ef42e12add707a1a7/gubajopuvet.pdfIn PDF document text
    • http://intertermo.nl/userfiles/file/59817881297.pdfIn PDF document text
    • https://1tlstar.com/storage/uploads/files/gotaxoviliwawasekek.pdfIn PDF document text
    • http://geo-equipe.it/userfiles/files/mowipadige.pdfIn PDF document text
    • http://limuzine.md/userfiles/file/8664667158.pdfIn PDF document text
    • https://www.artikel238.nl/emmwebbit/resources/ckfinder/userfiles/files/22755961474.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109080701208920.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/35092893617.pdfIn PDF document text
    • https://self-storage.sg/images/uploadedimages/file/4551928706.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/sotuxirazop.pdfIn PDF document text
    • https://rt9.rspo.org/ckfinder/userfiles/files/rufivovolexur.pdfIn PDF document text
    • 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_off0000e051.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE051 17228 bytes
SHA-256: 0d0cff8e3cd0953f9bd3cf5d215ee02072038400388396882681797e79657d58
font_01_sfnt_off00010d4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D4C 10588 bytes
SHA-256: c93a3ca18a70da0900bcec54eef9b60b9df95be03ae978c3295967dcd6a03e04
font_02_sfnt_off00012577.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12577 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1