Malicious PDF — malware analysis report

Static analysis result for SHA-256 88ff50f846cbdd01…

MALICIOUS

PDF

81.9 KB Created: 2021-09-05 02:52:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c9b080fea9f8ad6209f42e1c461de987 SHA-1: e5b4754164452b6373ae4368e54e470f61a91bc4 SHA-256: 88ff50f846cbdd01b48c0758310abb85a84a0c04684f2a0f7a5e0f5fb2d5aaec
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress upload directories, suggesting an attempt to lure users to malicious content or exploit vulnerabilities. The presence of multiple links on disposable hosting further supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aea7c3a2f77---15068592998.pdf In PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afb076363b5---vobakeremuniwesenaxadof.pdfIn PDF document text
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/1a52bd5dbc3d3c9862782d6458b60b85/712594962.pdfIn PDF document text
    • https://muachungbaohiem.com/uploads/userfiles/file/tuzovematajifumuwuzirejed.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/d2f786f7c3b3b22d3dd97ea09f5e0ead/97992486586.pdfIn PDF document text
    • https://equinox-e.com/upload/UserFiles/file/dasukirefagizajukofifewu.pdfIn PDF document text
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea7714388a---jedokufumi.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ada8145d1d6---37098584773.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/fd59c270f94ea6dfe2cafc751a374d4f/64290830001.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/cmikbuksd78s819usor33iko43/63382595905.pdfIn PDF document text
    • https://www.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078519341d7b---purovatunemezanosalosopa.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/27808711459.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7895260779---furigusotipawodoposenog.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/lugolunobup.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/kuzipozasikupiz.pdfIn PDF document text
    • http://staples1981.com/clients/b/ba/ba027a536d51c1d997ee76cae6dc9017/File/44618419756.pdfIn PDF document text
    • http://xinghui.co/upload/ckimg/files/202108081812274697.pdfIn PDF document text
    • http://cfh2.com/clients/d/d2/d2a7b52150a7a947468b52e9b7560e3c/File/87908064571.pdfIn PDF document text
    • http://panda-es.tokyo/yamituki-n/uploads/files/52578268693.pdfIn PDF document text
    • http://dochoiotovn.com/uploads/userfiles/file/tesatugewekerinujumuzol.pdfIn PDF document text
    • http://mazurubezpieczenia.pl/zdjecia/fck/file/51381487853.pdfIn PDF document text
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/zejofufejinesipadifa.pdfIn PDF document text
    • https://aksusu.com/upload/files/7046116654.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/98380413774.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/f04b0c9470082e5d60a2960fe062a03b/18851547328.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=koyo+spherical+roller+bearing+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_off0000da7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA7D 11044 bytes
SHA-256: 1fc971a1d0b02b97a421b9573befdc7fa0a2e45d64d6ff9d13e02d39f9f9a476
font_01_sfnt_off0000f3ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AB 17404 bytes
SHA-256: bc57f3d0a09ebf1ab83e20569d3ddb1f6218a39b7eda24df914eb157954e36c8
font_02_sfnt_off00012175.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12175 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1