Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c5099be922ac42e…

MALICIOUS

PDF

90.5 KB Created: 2021-09-18 20:21:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 579c364014196b005afe1d14256aa10a SHA-1: 0042810d52a8d1bb55d5d243d1db44443fb3e050 SHA-256: 8c5099be922ac42e1807960457ca1fe6f96acf32170d724c6af55d4e2711a7d9
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to a link farm hosted on disposable domains, a common tactic for phishing or distributing further malware. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a deliberate attempt to obscure the final destination through a large number of redirects.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9765

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://4els.ru/uploads/images/files/femibidoxorewipa.pdf In PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/bezevetupibukada.pdfIn PDF document text
    • https://dalnoboy.com/data/filestorage/upload/files/44630697302.pdfIn PDF document text
    • http://fotofolliasanlazzaro.it/userfiles/files/78754205647.pdfIn PDF document text
    • http://www.radio-kum.si/data/files/suritanixax.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/foxusaza.pdfIn PDF document text
    • http://goref.ru/files/file/pezudoge.pdfIn PDF document text
    • http://entryexpress.online/chapter_images/files/19642727754.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cd1f6ebdcb---vorikulolafa.pdfIn PDF document text
    • http://sladkiy-ostrov.ru/userfiles/files/63055931054.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/44145463443.pdfIn PDF document text
    • http://dc-42351dc5a6b3.prshots.es/uploads/userfiles/1631023140/files/45479952440.pdfIn PDF document text
    • http://dokturmice.com/ckfinder/userfiles/files/88220515021.pdfIn PDF document text
    • http://thucphamchucnangmy.vn/uploads/files/kidufutedavifobefuremuk.pdfIn PDF document text
    • http://boekenwinkelindex.nl/images/uploads/84969825844.pdfIn PDF document text
    • https://ww150007.linebot.net/upfile/files/20210903064613.pdfIn PDF document text
    • http://hairfibers24.com/upload/file/41158467807.pdfIn PDF document text
    • http://bsa.by/ckfinder/userfiles/files/19697384413.pdfIn PDF document text
    • http://marathon-gexin.com/Uploadfiles/files/96878363315.pdfIn PDF document text
    • https://dodatnojamstvo.com/userfiles/file/63419690897.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/77227565064.pdfIn PDF document text
    • https://talaa-obour.com/webmisr/uploadwebmisr/file/19938823462.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/bosebebupezapuxefuf.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/kekibuwetifosijiwazorelad.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/74073134797.pdfIn PDF document text
    • https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/16131da2d9e3ed---62914306822.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=passive+vs+active+voice+in+writingPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5ED 18300 bytes
SHA-256: f6ec9fc5d28600bbed69211acaf04e92ebbfd36aabd856dfb5ed7a6076e6da93
font_01_sfnt_off00011512.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11512 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012d29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D29 10512 bytes
SHA-256: 45e54a489b52f956f134e268764d3ca7d504ad7f357d2b2dbd4f337490e3a8f3
font_03_sfnt_off00014552.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14552 16448 bytes
SHA-256: 0e4cde3d5bdd5452960de995a4807c8da4ec665155a9812e2f8e54e6c49b7878