Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9b6726fab6f3a39…

MALICIOUS

PDF

80.0 KB Created: 2021-09-03 00:34:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 9612d07a91a2e356405b6b9bb5ba2ef4 SHA-1: 7cba6e1a13d3ff17dbaf2be6d1bcecbf85cae164 SHA-256: b9b6726fab6f3a391010a01bf80582f56ad78da79d4a164b1832ab9b377719b0
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains a link farm pointing to numerous URLs, many of which are hosted on compromised CMS uploads or disposable domains, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://pousadamarazul.tur.br/wp-content/plugins/formcraft/file-upload/server/content/files/160983100dd9dd---guvakinuvizivejekevajuwul.pdf In PDF document text
    • https://suacuacuontoanphat.com/upload/files/feviwejawopo.pdfIn PDF document text
    • https://fa-vietnam.com/webroot/img/files/91406172852.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606faea8c10f6---54585958313.pdfIn PDF document text
    • http://nowator-zpu.pl/userfiles/file/fiwemovalopiwuwaxifalig.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608516a136a0a---87501023932.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/sidujedawosasimobaj.pdfIn PDF document text
    • https://premium-house.uz/images/file/rakodanagexeku.pdfIn PDF document text
    • https://rosenstein.lu/userfiles/files/jejirawezirolikebakab.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/malofuwu.pdfIn PDF document text
    • http://hajnysport.cz/FCK_userfiles/file/11076282271.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d2da5e97cef---mowatovevit.pdfIn PDF document text
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/bdb90ce7d3e2c266bfb2ee0941851399/1077246414.pdfIn PDF document text
    • http://paliukenas.lt/i/File/29852677988.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd54790174b---kedew.pdfIn PDF document text
    • http://licausi.it/userfiles/files/gegesebusomarusovolo.pdfIn PDF document text
    • http://www.predia.cz/userfiles/file/59311737302.pdfIn PDF document text
    • https://akvaguru.hu/user/file/kojewegoxowigitatiloja.pdfIn PDF document text
    • https://micsys.in/userfiles/file/mafejonazixikipuxizugu.pdfIn PDF document text
    • http://eg-connect.com/uploads/editorfiles/file///97637618444.pdfIn PDF document text
    • http://beerskiboot.de/img/upload/file/3524248651.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=esercizi+fascite+plantare+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_off0000d4d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4D1 10536 bytes
SHA-256: 67e1f7858e40042bd947010cce40a28be18e8613d47921e4a45abebf62093d41
font_01_sfnt_off0000ecf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF2 17716 bytes
SHA-256: 36117544c1c4d4375f6eb92d6de46f28c824a854b444000b644f293c6dc08b71
font_02_sfnt_off00011a41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A41 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1