Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab39c5d841462bdd…

MALICIOUS

PDF

87.2 KB Created: 2021-09-15 00:20:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 64124fff696dfd76f8813380671f118f SHA-1: 6579ff98a5cbd22ff1ce82381c6ac76aaf52ada9 SHA-256: ab39c5d841462bdd85e19e9788718b9152d91ca8af13c1b36898a3f16afacdc9
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, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The embedded URLs suggest an attempt to redirect users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=pokemon+tower+defense+without+flash PDF link annotation
    • http://www.valathors.com/ckfinder/userfiles/files/49065787053.pdfIn PDF document text
    • https://drproperty.in/userfiles/file/jupifuwunavuvo.pdfIn PDF document text
    • http://melodylavernebettencourt.com/media/file/tupajixapirexefu.pdfIn PDF document text
    • http://zenithmetals.com/files/39825549537.pdfIn PDF document text
    • https://trompis-tondschungel.de/userfiles/file/sivapazexita.pdfIn PDF document text
    • http://re-media.ru/foto/ck/files/37692502932.pdfIn PDF document text
    • http://brandweeramsterdamamstellanden.nl/userfiles/file/sepozupimaviwobavi.pdfIn PDF document text
    • http://nepodoshlo.kz/ckfinder/userfiles/files/wezagejepitejejugax.pdfIn PDF document text
    • http://propack-th.com/image/upload/File/lunerezitubazozil.pdfIn PDF document text
    • http://bajcsidavidfoto.com/_user/file/tedasenarakesevosomiwusuk.pdfIn PDF document text
    • http://scherzerpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vosanugirija.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/92115390065.pdfIn PDF document text
    • http://f-okinawa.com/img/tmp/files/busawe.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614111574e4f0---xurudagarimafi.pdfIn PDF document text
    • http://mosme.org/uploadfile/files/56972508909.pdfIn PDF document text
    • https://llibreriaha.com/img/events/file/kuxuzipiri.pdfIn PDF document text
    • http://wxbeimei.cn/upload/ckimg/files/202109011805219991.pdfIn PDF document text
    • https://aannemingsbedrijfbarthulsbosch.nl/userfiles/file/42162239276.pdfIn PDF document text
    • https://wlao.on.ca/wp-content/plugins/super-forms/uploads/php/files/3bc135bc6b33c94ef141fe55050515a0/totuwedu.pdfIn PDF document text
    • http://floramarble.com/uploads/kotejojirepidijopanar.pdfIn PDF document text
    • https://blokhol.com/upload/files/fidevikidijuruze.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161402bf6ece56---movemarenuxamawu.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_off0000f08a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF08A 17588 bytes
SHA-256: d138b0e9a615703229e51b2b24bccc60ff16e99971b09c8b6259958469338231
font_01_sfnt_off00011e2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2F 10896 bytes
SHA-256: 4f2fa062c5c6273f98ef51f4e8e71558129a825c326ff5c8250e61d3d5dc4dee
font_02_sfnt_off00013748.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13748 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1