Malicious PDF — malware analysis report

Static analysis result for SHA-256 41acd1de8cde5452…

MALICIOUS

PDF

78.9 KB Created: 2021-09-07 11:18:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5ba0d94ccc852da9c67135dce64f83a1 SHA-1: 82de6a03f772ab0ccc7eddb0c6cc6772f405466f SHA-256: 41acd1de8cde54524fa57c216d01b810060c89e978037c68f32830974691f933
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links pointing to potentially compromised or disposable hosting sites, suggesting a link farm or phishing lure. The presence of external URIs and link farms indicates an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://ltssinternational.com/res/wysiwyg/file/97764436589.pdf In PDF document text
    • http://namjapizza.com/app/webroot/files/sudosatok.pdfIn PDF document text
    • http://instalater-macecek.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/kerowenubifafep.pdfIn PDF document text
    • https://markiza-trade.ru/admin/ckfinder/userfiles/files/jesoxuwegatebixetiloxun.pdfIn PDF document text
    • http://irinaburmistrova.ru/files/58375255736.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160b5bfec2a69c---4776015164.pdfIn PDF document text
    • https://tungqibiotech.com/upfiles/editor/files/30502274988.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160947cc1ca739---64579743739.pdfIn PDF document text
    • http://yasaitogo.com/uploads/files/rulikisekadevefiwomuw.pdfIn PDF document text
    • http://camwater.org/media/files/91767962035.pdfIn PDF document text
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a3dd5727d27---timise.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-5-22/20210522022141814174.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160c406558d8d3---93243839764.pdfIn PDF document text
    • https://greyquotient.com/wp-content/plugins/super-forms/uploads/php/files/d76a8c289108b3a69696ca27e8a3c98e/89618771189.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/89605561298.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/50986689267.pdfIn PDF document text
    • http://ticaproduce.com/ckfinder/userfiles/files/tizada.pdfIn PDF document text
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/liragedi.pdfIn PDF document text
    • https://crbz.ru/userfiles/file/pukeligoligofutosuf.pdfIn PDF document text
    • http://naphogacomposite.com/upload/files/gomude.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/begelu.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aec1cd1e22e---lewovamuzisuzajodaxowased.pdfIn PDF document text
    • http://szao-spb.ru/images/news/file/41110476024.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/vfik94aelj161tcgaclm2otdun/xisije.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=cours+anatomie+physiologie+humaine+pdfPDF 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_off0000cdb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDB6 18368 bytes
SHA-256: d241b1281c1d41bd03187b2f31fa6b63a8d6cf66b6f44ee996887e8037490313
font_01_sfnt_off0000fbb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBB4 11192 bytes
SHA-256: ac8deae603dd891663e1877bfc82440328069f3e143274753c0f2199c8dfc6bb
font_02_sfnt_off0001158a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1158A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1