Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b5346430c3cfca…

MALICIOUS

PDF

78.4 KB Created: 2021-09-18 03:21:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4a446d2e217a534ff8b27868f71076bb SHA-1: 88e2b19cb0bab328db2eca686c56c8aac3db8a2b SHA-256: 21b5346430c3cfca0dc1c8bfe551bc83b2846d250c2dd67702445a469555e9fb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting it functions as a link farm to distribute further malicious content or phish users. The presence of multiple external URIs and link farm heuristics strongly supports this attack pattern.

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://openkomm.yussfone-crm.com/userfiles/file/fixoruguxazikuzefisejusa.pdf In PDF document text
    • https://channeloflove.com/ckfinder/userfiles/files/70188391152.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/wojufuzeteg.pdfIn PDF document text
    • http://innotec-industrie.be/userfiles/file/90748229640.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/nmf7dqqb62k18di22c9ta948ei/50680698171.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135972054db8---xurobexosuf.pdfIn PDF document text
    • http://irths.com/upload_files/files/46649591790.pdfIn PDF document text
    • http://dinhvi5s.com/images/newtech/files/fokuwolebotijeboguv.pdfIn PDF document text
    • http://www.beverburcht.nl/upload/files/voditojituvipumoxula.pdfIn PDF document text
    • http://jjc-dev.com/userfiles/file/68278299179.pdfIn PDF document text
    • http://wuyioutdoor.com/userfiles/file/57149835377.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/dotazogugoxixuremogetino.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/tivuvinubiderovasamodif.pdfIn PDF document text
    • http://chemonova.com/FCKeditor/file/diwodasuxesujana.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161400488bbb4c---586737476.pdfIn PDF document text
    • http://giasuminhtam.com/Images_upload/files/46102810566.pdfIn PDF document text
    • http://turnyras.lt/Files/file/waduzuvosupataxazuja.pdfIn PDF document text
    • http://livestocktool.com/d/files/jakalobe.pdfIn PDF document text
    • http://easyhypermarket.com/userfiles/file/pejar.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16142280ff3f38---37440358398.pdfIn PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/1613a8285a2724---xokasimidu.pdfIn PDF document text
    • http://nhatrangpalace.vn/app/webroot/upload/files/6223797665.pdfIn PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/2018939950.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613195ce5038e---2799017948.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=top+down+bottom+up+processing+psychologyPDF 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_off0000cc7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC7E 17612 bytes
SHA-256: bcab9364665ca23908f400adc391e8ddbe0cb07145ee6ff496421a362894f635
font_01_sfnt_off0000f992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF992 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000111a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111A9 11200 bytes
SHA-256: cce193eb8e6043f7d32faa5dde42dcee5aa77271b561f676d24a7af91e5cd2fd