Malicious PDF — malware analysis report

Static analysis result for SHA-256 ee65344316b5f4ac…

MALICIOUS

PDF

80.0 KB Created: 2021-07-07 03:25:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 1c38e738dff98aa74e21a99ab49c4d4c SHA-1: efb08d035b8a5cd0beb8bec29b8344d15a6bf36f SHA-256: ee65344316b5f4ac1a05cd88a94f9cb8c051e851de146dea512adb72a000c9ec
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, identified by heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier also strongly flagged this PDF as malicious. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • 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://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f142be0b2e---46402088669.pdf In PDF document text
    • http://amadpich.com/userfiles/file/95815624497.pdfIn PDF document text
    • http://svatba-emi.com/uploads/pages/files/45847538823.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/ae24i0nl992j13pl79gi2bl46k/78240848184.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/5e7524949ea1de581756fdfb63f34b38/bubasebulukupu.pdfIn PDF document text
    • https://shotclock.ca/wp-content/plugins/super-forms/uploads/php/files/d0d4403553e4d37f3afc11742c25c587/nexazomitixiwuzipobet.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/e89a6f747daf69c2360d2b70951e31dc/pinironeti.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/d55a493dfe254a0fdde34b0d1b0d7c7b/subozikiti.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096794c4d92c---bupasugeveboge.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/bilaxitoxe.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc6239bf02---3053637040.pdfIn PDF document text
    • https://seitonsolutions.com/ci/files/kuliduxowisumubekuguwolev.pdfIn PDF document text
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/venoxozasiligukodakixap.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b844e9c3f28---23425892937.pdfIn PDF document text
    • http://bygreenpure.com/userfiles/file/82292197652.pdfIn PDF document text
    • https://anandamsanyal.com/userfiles/file/64493271995.pdfIn PDF document text
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/160adfd7023f9c---rupaxowilezojunadejezij.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/lepud.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a4e01f02c3d---gowosanizokitakuwarezi.pdfIn PDF document text
    • http://dorisemitchell.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/90301293920.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160892cf4e73ff---vakizagaxefivexejimow.pdfIn PDF document text
    • http://www.hcibatiment.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a907e038aaf---7956933604.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073be75928e0---vubotuzonuvidivi.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/vdpfpnd3gfs16r9qqc10j7gi6e/galunumoxikazil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=the+young%27s+modulus+of+the+material+of+a+wire+is+equal+to+thePDF 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_off0000cf12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF12 17980 bytes
SHA-256: a03780b0250443e7efdb805dc9e759386c25760d0ef7e7411ef0b1f009b58e45
font_01_sfnt_off0000fe26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE26 11244 bytes
SHA-256: 31304969594542d216a95d76957b760c42e877a97ae3304eeac19889c55816d6
font_02_sfnt_off000117eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1