Malicious PDF — malware analysis report

Static analysis result for SHA-256 641fb57308f2b949…

MALICIOUS

PDF

68.9 KB Created: 2021-09-16 15:24:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 9b9646e4928cd8a0d2c28bbf9225427d SHA-1: 75482c099cbc99dc2dba5baecfeeb543e57bb8b7 SHA-256: 641fb57308f2b94917e2f625bfd35b76b6709db8483b09c3a44680f3d29643a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous links to external websites, many hosted on compromised CMS uploads, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614200e041e18---57160063048.pdf In PDF document text
    • http://nirmalapublicschoolerumely.com/userfiles/file/pavikex.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/91051325564.pdfIn PDF document text
    • https://1snrpaulista.com.br/ckfinder/userfiles/files/rotuvaxopekavanejanul.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/ncmkofjqiv2qlh2olmdhq156d1/41539546809.pdfIn PDF document text
    • http://ikkosushi.com/uploads/files/xopexebisuzefopogekaje.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/91674348867.pdfIn PDF document text
    • https://argentinaproduct.com/ckfinder/userfiles/files/32972336092.pdfIn PDF document text
    • http://netichikawaya.com/userfiles/file/18920274904.pdfIn PDF document text
    • http://vanillasky-ch.com/images/files/37947780401.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132fa01cc137---31592695989.pdfIn PDF document text
    • http://hnfhdc.com/UpLoadFile/2021090114510047384.pdfIn PDF document text
    • https://tungafilm.com/dorceiys/ckfinder/userfiles/files/kujaxuw.pdfIn PDF document text
    • http://urparitet.ru/admin/ckfinder/userfiles/files/vofezavirad.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/xisus.pdfIn PDF document text
    • http://racecross.com/upload/edito_fckeditor/file/42993256163.pdfIn PDF document text
    • http://n2nnetworks.com/files/others/96920270154.pdfIn PDF document text
    • https://terminarz.online/kosmetyczka/krakow/files/mukogirovovataj.pdfIn PDF document text
    • http://x-site.by/upload/editor/files/gamosovubale.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c77b30960b---91915646880.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/xetekanedin.pdfIn PDF document text
    • http://ryukatsu.com/userData/board/file/37613038816.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/tudozup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=mms+no+subjectPDF 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_off0000b133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB133 14964 bytes
SHA-256: ccf828aaa35440575ac6e2266afb9f4da5546be743a9af328f868920ed51d7ab
font_01_sfnt_off0000d66a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD66A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE81 10352 bytes
SHA-256: 5e699e9d07c8df87dcee052a5cde44d91f816b73308c61fa355610451a19d2b1