Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa1a811ad3833bae…

MALICIOUS

PDF

80.8 KB Created: 2021-09-09 01:47:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: db261124ac0ae3cd2143e8808a9a5198 SHA-1: 1de58cf710d24f9dc5e47d2ccafaca284914d228 SHA-256: aa1a811ad3833bae744397a02b395a45d0eb4eeddef2bb01c68d0f0843ddef93
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to files hosted on compromised CMS upload directories. The ML classifier strongly flagged this PDF as malicious, and the heuristic rules indicate it functions as a link farm. The primary purpose appears to be redirecting users to other malicious documents or potentially exploit-hosting pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139377e56d74---sifijonabugu.pdf In PDF document text
    • http://ilonew.tasksplan.com/ckfinder/userfiles/files/fizivubefagilubara.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/25924078162.pdfIn PDF document text
    • https://futurefacesmiami.com/uploads/file/masijufileruk.pdfIn PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/24610875478.pdfIn PDF document text
    • http://dribblebar.pl/userfiles/file/tubupidelomudixobizaz.pdfIn PDF document text
    • http://saaretravel.ee/images/file/67409703344.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/naxuponogozuvifawed.pdfIn PDF document text
    • http://www.saveurspoitoucharentes.com/admin/ckfinder/userfiles/files/muluxivezamuradamekukux.pdfIn PDF document text
    • https://pasarangroup2.com/contents/files/22066431603.pdfIn PDF document text
    • http://leeharringtonhomes.com/userfiles/file/63160579238.pdfIn PDF document text
    • http://murasakijr.com/uploads/files/6511388874.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/cflvvue19csseii3oqfp5qm71v/jekarebisuwofu.pdfIn PDF document text
    • https://matharu.ae/userfiles/file/nomofatujuvu.pdfIn PDF document text
    • http://akademia-jedenastka.pl/zdjecia/fck/file/jezafoxatatifumaf.pdfIn PDF document text
    • https://deshpanday.com/ckfinder/userfiles/files/wameko.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/19269613629.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/fitekadupolijij.pdfIn PDF document text
    • http://vonschickenfremont.com/uploads/files/94589545143.pdfIn PDF document text
    • http://mazdooradda.com/userfiles/file/714998689.pdfIn PDF document text
    • https://vhcvietnam.vn/ckeditor/images/files/85036744604.pdfIn PDF document text
    • https://imagebrandstudio.com/userfiles/file/450619343.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/73170ebfd770b88f9993d8566cfe0403/73493126208.pdfIn PDF document text
    • http://opgzvh.hr/upload/file/13331603426.pdfIn PDF document text
    • https://parlagame.net/calisma2/files/uploads/dedezipugulo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=comment+acheter+application+android+sans+carte+bancairePDF 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_off0000d61b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD61B 18396 bytes
SHA-256: a50bfef5bc61e2136c112cf8e0a4d8791f1f69f56382db08d3d22defa53b587a
font_01_sfnt_off0001042f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1042F 10952 bytes
SHA-256: 8c4df07a0faf46edb280183b5eddf18dfda10f7f86648031efa129a5aba0bd53
font_02_sfnt_off00011d21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D21 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1