Malicious PDF — malware analysis report

Static analysis result for SHA-256 13f866f038cf179b…

MALICIOUS

PDF

105.4 KB Created: 2021-09-02 22:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 71b16ce054dcab8c692398d1c7b22b3b SHA-1: 4185e7012b201d324961c9ced2e015534e286b34 SHA-256: 13f866f038cf179bbe8a3502d2b5df3637b2c4ff8763fe2e0695df0b7ecc52d8
156 Risk Score

Malware Insights

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

The PDF file contains a link farm directing users to multiple websites, some of which are hosted on compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The primary attack pattern involves luring users to external sites via embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.startservis.sk/novy/ckfinder/userfiles/files/5267990052.pdf In PDF document text
    • https://autotrans911.com/thread/admin/uploads/file/62392584535.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/tidodggucs93466c45iqi6rqvv/99154320484.pdfIn PDF document text
    • http://z500.si/files/23557118229.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5761a3df9---12092055350.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/99961987411.pdfIn PDF document text
    • http://shreejians.com/userfiles/file/bugunomex.pdfIn PDF document text
    • https://piataafacerilor.ro/app/webroot/files/userfiles/files/xegojifokipi.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/6a6ba0e07f0985833462ddca9d44fbf9/gusowapagep.pdfIn PDF document text
    • https://rzfmuhasebe.com/userfiles/file/40194997720.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/39085156212.pdfIn PDF document text
    • http://wakesup.org/userfiles/file/66024018864.pdfIn PDF document text
    • http://top-conversion.ru/ckfinder/userfiles/files/ravepotatuliwobowipuvaxu.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a1034819e88---xetor.pdfIn PDF document text
    • http://clair-environnement.eu/catalogue_dynamique/file/25409880026.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/36286622073.pdfIn PDF document text
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/6cac35a3e1db08567aa80a2998f83fb1/59513743363.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1feaba1ba4---3163065555.pdfIn PDF document text
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/j7iaigvhlmgevqodlnfrj9sju8/vepekojoronapagixinuzo.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb1e795835---53703578173.pdfIn PDF document text
    • http://mopi.eu/ckfinder/userfiles/files/32028292478.pdfIn PDF document text
    • https://lee-trading.tw/archive/upload/files/35081660512.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/a456df7927db703a73bb9f9452b25d20/24065157031.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/5897210785.pdfIn PDF document text
    • https://debcopharma.com/userfiles/file/rijuwonazif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=materi+hak+asasi+manusia+pdfPDF 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_off00013ca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CA2 10780 bytes
SHA-256: 044475edf8d149c6d124c8922e2a94387d430c2f8e7663f73adca29a2c569c8c
font_01_sfnt_off0001553d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1553D 16240 bytes
SHA-256: 287f4029f1fc7f2ea1ab8423da30cc8d1917fd5f9314b8cb8fccf0c47ff066df
font_02_sfnt_off00017f84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17F84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1