Malicious PDF — malware analysis report

Static analysis result for SHA-256 43c57d57eb4ba674…

MALICIOUS

PDF

82.2 KB Created: 2021-09-02 03:12:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 7032ddd24a29b59d0c565488a380d0a5 SHA-1: efa449151869752f630700041405b39f750c54c3 SHA-256: 43c57d57eb4ba6747ab065e6a592634217a9b113f1d4b0a8cdc86733df556e84
156 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating it is a link farm hosted on compromised CMS platforms, directing users to potentially malicious content. ClamAV and an ML classifier also flagged this PDF as malicious, specifically identifying it as a phishing trojan. The embedded URLs, such as the one pointing to compromised WordPress upload storage, are the primary indicators of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://deckdreams.ca/clients/3/34/34055ef41782f8f15ebf372c1e39ecad/File/91271741202.pdf In PDF document text
    • http://bursaceyizgelinlik.com/images_upload/files/gogonimuxupito.pdfIn PDF document text
    • https://aviseco.ro/userfiles/file/nuvadatidiwatezidos.pdfIn PDF document text
    • http://seamacros.com/upload/file/95232859818.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16108b2bfbf4fa---pobomupo.pdfIn PDF document text
    • https://briljant-maleri.se/UserFiles/files/78336507284.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a445fb359f6---65329522137.pdfIn PDF document text
    • https://voicelux.ru/wp-content/plugins/super-forms/uploads/php/files/374ef17de11c43aa9ae44a3f8b4ca26a/fupaxevufibavo.pdfIn PDF document text
    • http://samnakthodrahassob.com/userfiles/file/jowuvibona.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16106b6b64ede0---47786963014.pdfIn PDF document text
    • http://toshiteriyakiburien.com/uploads/files/96939707586.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/16501211663.pdfIn PDF document text
    • https://aadhaarretail.com/administrator/imagetemp/file/kurif.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a4e992be98---61779853591.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3de84c72e---xeluvokosotuwalikin.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c89869c7423---vejivenizopotoxuwoxevupen.pdfIn PDF document text
    • http://toshiba-center.ru/uploads/files/61848878582.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/5f7o69mc7erbp0uavais8eba73/novogowedenelom.pdfIn PDF document text
    • https://camphacement.vn/upload/files/lubepedemug.pdfIn PDF document text
    • http://weifong.tw/fckimages/file/vozojufejo.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/57j8udr934tjd5q5t0vdtd0ir1/lelemepi.pdfIn PDF document text
    • http://abwessex.com/uploads/files/zajul.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b467e490207---depazuko.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/34445273914.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=conversion+chart+gallons+to+quartsPDF 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_off0000dc96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC96 17352 bytes
SHA-256: 6dcf96ed6ab6b833706c79426df77440814dd34857ab5f60cead9f6d2f401fab
font_01_sfnt_off00010972.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10972 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012189.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12189 10852 bytes
SHA-256: 52bfacf7370f0b290c54492041e69dfbbd889ba141219a28db2d8aba48362689