Malicious PDF — malware analysis report

Static analysis result for SHA-256 106090233a1c88fa…

MALICIOUS

PDF

104.9 KB Created: 2021-10-05 19:46:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 5e766925f121dc6c30c9e44bf12d1f3d SHA-1: 3af17a4762ddd4bdcd32ff158b6fa745654fb3f6 SHA-256: 106090233a1c88fa32e957025200dcf9daff32af89835b9bcdfe0e8696d803a9
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with several heuristics indicating it functions as a link farm. Notably, one URL points to a compromised WordPress upload directory, suggesting a potential distribution or hosting mechanism for malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://iucecb.com/files/file/56776232069.pdf In PDF document text
    • http://snft.ro/media/file/tazekukizukawoj.pdfIn PDF document text
    • https://ajur.rest/uploads/userfiles/file/zizekatezu.pdfIn PDF document text
    • http://xsteelstock.com/d/files/buduno.pdfIn PDF document text
    • http://kursverwaltung.fit-n-essen.ch/ckfinder/userfiles/files/girorozukitetazivegofuwo.pdfIn PDF document text
    • http://kwartetproforma.com/userfiles/file/vemuzeg.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/80480668037.pdfIn PDF document text
    • http://studioarchterreni.it/userfiles/files/livovuxolarekikurenuzuse.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1613392bc492ee---xepevosakan.pdfIn PDF document text
    • https://nocenzura.space/web/img/podborky/files/lumexokupixolegimed.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16137838719188---2793400150.pdfIn PDF document text
    • https://cjsc.se/ckfinder/userfiles/files/98821052149.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/99869075261.pdfIn PDF document text
    • http://shoreluxurylimos.com/userfiles/files/44797842802.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615b3a34926de---27936317328.pdfIn PDF document text
    • http://zamgph.com/FCKeditor/editor/filemanager/connectors/php/uploads/file/01030832575.pdfIn PDF document text
    • http://ammk.sk/userfiles/file/29940309981.pdfIn PDF document text
    • https://brtim.com/uploads/wysiwyg/files/luxusumerow.pdfIn PDF document text
    • http://glassick.com/userfiles/file/pinuzefuzarox.pdfIn PDF document text
    • http://surveycook.com/upload/tmp/202109/file/mabuf.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d98a2da662---65276485349.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/16158696df2f20---jefakoli.pdfIn PDF document text
    • https://bizimpin.com/calisma2/files/uploads/wajojivonifo.pdfIn PDF document text
    • https://998.geektic.com/geektic/files/34941725188.pdfIn PDF document text
    • http://musicincw.com/fckeditor/userfiles/image/75323852978.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=two+types+of+yeastPDF 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_off00013414.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13414 19612 bytes
SHA-256: 07a66215aeb7b640e3fbe7c8df69796ab522a820a1a09a4e8fbeb0aeec19d91c
font_01_sfnt_off00016720.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16720 10172 bytes
SHA-256: 8b251675f45b1a0b480321efc1fb5ff98ac1de829fd81d932783bd85fad3778f
font_02_sfnt_off00017e37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17E37 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1