Malicious PDF — malware analysis report

Static analysis result for SHA-256 fc7302b3aedebe74…

MALICIOUS

PDF

74.7 KB Created: 2021-10-09 03:51:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1dc64cfc331c8c01cfb2824a4ef8160e SHA-1: 4012c878c3ba807efb346bb78e4e2a21bc963208 SHA-256: fc7302b3aedebe7427770033a6b883b08e1aa9dd002e207bd867a20a14926bd5
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, with numerous embedded URLs pointing to potentially compromised or disposable hosting sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://vekosgroup.ru/userfiles/file/punoxelidixaladegipevume.pdf In PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615b93f585788---vijadonamipofuku.pdfIn PDF document text
    • http://synowka.pl/galeria/file/69854913489.pdfIn PDF document text
    • https://pulsekb.ru/admin/ckfinder/userfiles/files/33150598379.pdfIn PDF document text
    • http://amicalelaique-guyancourt.fr/ckfinder/userfiles/files/53736767021.pdfIn PDF document text
    • https://clap-bas.com/userfiles/file/34297362342.pdfIn PDF document text
    • http://praguetransfer.com/files/file/nukan.pdfIn PDF document text
    • http://hcstonetw.com/uploads/files/202109282318509253.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/6849991841.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161392d60a7b13---nopariravolum.pdfIn PDF document text
    • http://gamecoast.by/uploads/files/61088495291.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/7c68d4d67da577586a91f57b71558bfe/sivezuvovuwuve.pdfIn PDF document text
    • http://logicparcel.net/uploadsEditorfile/piranoso.pdfIn PDF document text
    • https://rotitelor.com/contents/files/54227245793.pdfIn PDF document text
    • http://sweet-sugar.de/images/uploadedimages/file/lanekoku.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1614e5f434e024---49599242693.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16141378bb768b---temusef.pdfIn PDF document text
    • https://delaneyllc.com/ckfinder/userfiles/files/39083596711.pdfIn PDF document text
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16141cacdb87ef---sejufozojujipipugakap.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/rufogaxibir.pdfIn PDF document text
    • http://contextuae.com/resimler/files/19071509336.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=confidence+interval+sample+proportionPDF 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_off0000c0c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8DD 10880 bytes
SHA-256: 7b9e7980b46bbce4be13e1364962e14baa013b5b086c0c7531ee6e91a0ab4dc7
font_02_sfnt_off0000f20a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF20A 16788 bytes
SHA-256: 388198c1f51b8ef5947bf70bc491cb00d31b9010b34649798f449b9b70533ce0