Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a81debd4bfd6fcd…

MALICIOUS

PDF

114.2 KB Created: 2021-08-09 02:15:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 53fb47c54f2d3123a625ad3c0401c475 SHA-1: 7dce1a206246e7f5160204d7bc9afbce97b511a8 SHA-256: 1a81debd4bfd6fcd42aea416b7bb13c46dabb957d4e5360263bf98b3217456ee
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to potentially compromised or disposable hosting sites. The embedded URLs and the overall structure suggest an attempt to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

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://cayxaotamphan.net/userfiles/image/file/birevifugolepafafa.pdf In PDF document text
    • https://gamasteel.net/userfiles/file/nadaxuxofipetuwo.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/160830af6c27f2---80037372554.pdfIn PDF document text
    • http://sbnjl.com/userfiles/files/lemujaxorupoxolevugusaji.pdfIn PDF document text
    • https://costabravas.com/uploads/localidades/files/wimam.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/80452120550.pdfIn PDF document text
    • https://ebal.ro/app/webroot/files/userfiles/files/35640211013.pdfIn PDF document text
    • https://pacpartner.net/images_client//imagesfile/jovodotolenudubanuv.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2b5addd1e1---magatufakafelate.pdfIn PDF document text
    • http://weiken-rc.com/upload/files/39039498689.pdfIn PDF document text
    • http://imcborivali.org/userfiles/file/3698240363.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/0aa12120e3d0c7c6b6a6dd825f4aea7b/59737449965.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/xumekewow.pdfIn PDF document text
    • http://uptownchantilly.com/uploads/files/7234102419.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/cad71d79f3376a8e2a59af3d29e2aaa2/nivemido.pdfIn PDF document text
    • https://hyosungulf.com/uploads/file/8785414640.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/7295f3efcaeb049c01b16e02c5d41c69/vitivi.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/82371727469.pdfIn PDF document text
    • http://ambvet-trefontane.eu/userfiles/files/pisubivuledodolese.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/14qu7l4e45iq8vn5i1m8pc1bf1/99264967745.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608446121562c---renafiriwasezun.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/28d0024e84ffe24282dd54a57cc23ba9/34931453830.pdfIn PDF document text
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608f9b4465ad9---35442393321.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/sitl0l0kv8htes14aenfkd51l7/nozivubemufuvasusima.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=hojas+con+lineas+para+escribir+e+imprimirPDF 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_off00015cea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CEA 17540 bytes
SHA-256: 8c439c0050fd1f740bc65e50178bcb76ae8e9693a2e1d3e69ea875df0293cbd7
font_01_sfnt_off000189a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x189A0 10700 bytes
SHA-256: eff1983216fa2fee96686e67018ea3536ed1dea03ab68fdacd3b07928b1309bb
font_02_sfnt_off0001a1d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A1D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1