Malicious PDF — malware analysis report

Static analysis result for SHA-256 544f37ed64085640…

MALICIOUS

PDF

80.3 KB Created: 2021-09-06 20:03:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: d342aaed48d10b60d8f3d715e23b8c8e SHA-1: b83bee21d4ed4cd1cb8d85ec403d12bd5a4f8478 SHA-256: 544f37ed640856401d4051aa01950ff23b4415a4829545edcf23be54d3b2805b
156 Risk Score

Malware Insights

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

The PDF document 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 distinct hosts, some of which are hosted on compromised CMS upload storage. While no scripts were directly extracted, the nature of PDF link farms often involves JavaScript execution to redirect users, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://alpha-th.com/userfiles/file/vatutivijopokepeb.pdf In PDF document text
    • http://whs1979.net/clients/65916/File/87916368463.pdfIn PDF document text
    • http://zartmobilia.com/userfiles/file/20210831171520.pdfIn PDF document text
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131d405e6d46---23322911817.pdfIn PDF document text
    • https://nhanloc.net/userfiles/file/jujutobijudobag.pdfIn PDF document text
    • https://thefertilizerproductionline.com/d/files/69774732474.pdfIn PDF document text
    • https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/d9qenpcv59l8825795ro7e01tq/fosijemadaza.pdfIn PDF document text
    • http://healingtown.org/userData/board/file/tufesababufubowafevaradu.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/fuxukerofum.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/653c22103aef0040d51cd4ddf026d45e/zurilifemate.pdfIn PDF document text
    • http://coytex.net//ckfinder/userfiles/files/51870968395.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/fj8967ikm00u0tgn816voiplk1/27900055471.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab12ece09c5---55384368716.pdfIn PDF document text
    • https://indobaliart.com/sitefiles/file/mojebugusabefamusoka.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094d5d271f6f---dezuzugisudegizimibusivek.pdfIn PDF document text
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1611d2d052953e---13086187288.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/b033b915facf79a1a53e76933f1e9ba0/55992506149.pdfIn PDF document text
    • https://www.edmcenter.xyz/ckfinder/userfiles/files/zexix.pdfIn PDF document text
    • http://adbuilder.at/ckfinder/userfiles/files/50732331939.pdfIn PDF document text
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160ab9e222a96e---nemilisedewuzewitokix.pdfIn PDF document text
    • http://italianopizzeria-pg.com/uploads/files/tebop.pdfIn PDF document text
    • http://scvumaichiramen.com/uploads/files/72413416790.pdfIn PDF document text
    • http://theonejsc.com/userfiles/file/73815123789.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/21186568602.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=dressmaker+sewing+machine+998b+instruction+manualPDF 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_off0000d369.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD369 16756 bytes
SHA-256: 3b098ae5dec615da928f55a898c2bc21bf51d97305482cc453d857ffd1cc37bc
font_01_sfnt_off0000fe42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE42 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011659.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11659 11472 bytes
SHA-256: 7913db1ae5d963c3f4f261c6f8d61ca4c270dfa87db837849b3eb663a3b1ca2a