Malicious PDF — malware analysis report

Static analysis result for SHA-256 c310fb4d8c19d170…

MALICIOUS

PDF

83.4 KB Created: 2021-09-09 11:47:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 768f53874a619a431b4c08ad6bedb256 SHA-1: a4682c2ef6c0dde130f07fd6d9bae16e7c134182 SHA-256: c310fb4d8c19d1707c852ecc7eb10f63d5cc0a8305d208dd84e5560d045d73bd
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous external URLs, many pointing to compromised or disposable domains, indicating a phishing or malware distribution attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the nature of the link farm and the PDF format itself often implies the potential for embedded JavaScript or exploits to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://hometutorsdelhi.com/userfiles/files/87298878382.pdf In PDF document text
    • http://moderncarrent.com/user_img/files/58015816350.pdfIn PDF document text
    • http://mamnonsaokhue.vn/app/webroot/files/ckfinder/files/dilivuditafexutu.pdfIn PDF document text
    • http://elandtour.com/FileData/ckfinder/files/20210904_99D08DF306B8A8E1.pdfIn PDF document text
    • https://jnvhardoi.org/ckfinder/userfiles/files/75219022023.pdfIn PDF document text
    • http://cartopack.be/Images/file/69921057751.pdfIn PDF document text
    • https://beysukonaklari.com/ckfinder/userfiles/files/rogurigukafawo.pdfIn PDF document text
    • http://www.deep2001.com/images/library/File/55178659485.pdfIn PDF document text
    • https://propactionvehiclesuk.tv/userfiles/files/zejez.pdfIn PDF document text
    • http://kredoteka.ru/uploads/file/5990184090.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/genimigemuxalujiw.pdfIn PDF document text
    • https://pastijptoto.com/contents/files/34993372915.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/xelawutamo.pdfIn PDF document text
    • https://resicolor.com/upload/files/32864287662.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/3a60d544fd06bf2c703ed194e4888063/97663903928.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613670614fce4---971595567.pdfIn PDF document text
    • http://cuacuongiare.vn/upload/files/fevakoduborineriletime.pdfIn PDF document text
    • https://truongthanhco.vn/webroot/img/files/31573590288.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393ff8c910a---dabaguguguke.pdfIn PDF document text
    • https://torbay.ru/images/uploads/file/41654614803.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/xenotuwab.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/lobakotifuzabijalamegetu.pdfIn PDF document text
    • http://jcnjl.com/userfiles/files/verelimaruwo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=worksheet+calligraphy+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_off0000e094.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE094 10992 bytes
SHA-256: f2013696cbfe82f98aa536368d4aa2564d0fb50c7442d63535d90ab4c721785a
font_01_sfnt_off0000fa1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011231.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11231 18028 bytes
SHA-256: 4387e142419e5bcb0979267ad3138753a544f4ae64920c6372b5fb6233a42dfb