Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55855bda3d30a4a…

MALICIOUS

PDF

84.3 KB Created: 2021-09-05 01:47:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: be6948612967c3e8f9579426e235fa8d SHA-1: 7c85c6a5bc02e275288cbc49afbc5ffb9f39d6b0 SHA-256: b55855bda3d30a4a049c6ebb01ea48631a346211d774ff330ebc2710d2c19d4a
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous PDF files hosted on various domains, some of which appear to be compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure suggests the document's primary purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://monkey-do.net/userfiles/file/japupolet.pdf In PDF document text
    • http://bangtutrang.com/upload/files/barusu.pdfIn PDF document text
    • http://skrabl.pl/www/rpbd/fck/file/roliraxefefibowefixuzum.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/maxilisuba.pdfIn PDF document text
    • http://erbaytag.com/resimler/files/metirijodefigusodaw.pdfIn PDF document text
    • http://yalciniskele.com/imgup/file/60821500378.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1609f21ee56f33---xogilemanapu.pdfIn PDF document text
    • http://gancza.pl/userfiles/file/zotijanipuxowijazituveg.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/mazuniluwobikeb.pdfIn PDF document text
    • http://tsrmvolontari.it/userfiles/files/wulikek.pdfIn PDF document text
    • http://xycrusher.com/d/files/59238532580.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/f544d2294848d9b45ac67541c96fc26b/63061730689.pdfIn PDF document text
    • http://thibangoto.com/app/webroot/uploads/files/bukiwaw.pdfIn PDF document text
    • http://grandbarnettfamily.com/clients/a/a0/a01b80d98e57c38af56892ab55e7d82f/File/56664523334.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/060477c55056a725334d0b329e4cdd85/pajegufupelorolowuniza.pdfIn PDF document text
    • http://www.studiolegalefusimorelli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aee7425ad28---fevavunasigemuxotopeti.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1625301996.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210702122249175.pdfIn PDF document text
    • http://frigotechreina.com/userfiles/files/25952929490.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/14583570190.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/lidowapasu.pdfIn PDF document text
    • http://uspeh-kursk.ru/ckfinder/userfiles/files/86701770795.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=grade+6+maths+word+problems+worksheets+pdfPDF link annotation
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/161212e3430156---91790721954.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_off0000e3e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E9 17508 bytes
SHA-256: cdd7fcee3d6be93ef69669e409257f46d13a8ce067720ff22d5d32f4b622457d
font_01_sfnt_off000111d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111D2 11092 bytes
SHA-256: 70ac6990d15c39f44d153519a3de3d3dfeb8e49fd1de1460a9865a9f1fe1beee
font_02_sfnt_off00012b97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1