Malicious PDF — malware analysis report

Static analysis result for SHA-256 73b52e87807882aa…

MALICIOUS

PDF

80.3 KB Created: 2021-07-06 00:42:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 02c23f98383f4c330989b0c151274a4e SHA-1: a778e1e7dd033069975d48e2be18705217bdfcce SHA-256: 73b52e87807882aad50700146470b3f545e72ff3bc663c4d2b31d6ed15f6313b
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to domains that appear to be compromised or disposable hosting, suggesting a link farm designed to lead users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. The presence of external URI heuristics and the compromised CMS upload link farm further support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://lycee-elm.org/userfiles/file/reposimetezifedasewidoj.pdf In PDF document text
    • https://intrigantka.ru/images/userfiles/file/30275735914.pdfIn PDF document text
    • http://dentherapia.hu/files/file/10340851653.pdfIn PDF document text
    • https://transport-vehicules.fr/userfiles/file/novuvenowaratasekab.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/gbr5inf1fe0n96um1h3jeif491/84942985674.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/160dbb49cf1555---supubovugubavivufato.pdfIn PDF document text
    • http://lucann.com/Upload/file/woxisajejaze.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3065a03cd1---37544241304.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/rokefiviwijosewewov.pdfIn PDF document text
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/567c88094ac93279c43475cd9994e2ef/lasazebuvugisexinubefepu.pdfIn PDF document text
    • http://boekenwinkelindex.nl/images/uploads/raguxotetolenomonuduz.pdfIn PDF document text
    • https://africanresearchcenter.com/userfiles/file/44737870979.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/75801562283.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9cdd130ad---19138885812.pdfIn PDF document text
    • http://fonnepal.org/userfiles/file/35245919744.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b7fe3a1e53d---69209625994.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/prgjcop33rk0ssk6n9qoofse01/rokenujinon.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/8e8c08c93c215a3fa292ba6b8c96079f/19898271799.pdfIn PDF document text
    • https://vestol.bg/files/file/nazajilarigazaresebojabo.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/3176cbe50c81fcb762e268caf283a814/23838254556.pdfIn PDF document text
    • https://mebelihome.ru/upload_picture/sesazujit.pdfIn PDF document text
    • http://mobilesamara.com/img/files/file/lagukijabarekuk.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/89592131469.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/60977307979.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/9i6ed75amipfs1t8em7jg6jck2/34631420601.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=chord+bullet+for+my+valentine+acousticPDF 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_off0000d450.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD450 17284 bytes
SHA-256: c20a6612efa5355eccf3b7a93ef9406abc92b7faa4dcff00fb718a307a7de5e7
font_01_sfnt_off00010172.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10172 11192 bytes
SHA-256: ba05e237ea722ffc83058d73d36a18d7da2c1a1d769ef4ef3b2acf7a0011bdd3
font_02_sfnt_off00011b84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1