Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b094b7912159550…

MALICIOUS

PDF

71.0 KB Created: 2021-09-26 21:37:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bf72d4d595139cded3e7c34f141e15ff SHA-1: bf8449eef5ae262ce501149c4e09420132130302 SHA-256: 8b094b79121595507d8cc40a1b90855eadacac355d26233b621d14d0f7f268bf
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to multiple domains, some of which appear to be compromised WordPress sites, suggesting an attempt to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://ventiliatoriai.lt/js/ckfinder/userfiles/files/rosusama.pdf In PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/161304f0b2fc3f---67523112356.pdfIn PDF document text
    • http://tcyy88.com/userfiles/file/2021090607443273499.pdfIn PDF document text
    • https://feniks9.ru/ckfinder/userfiles/files/gezonixusej.pdfIn PDF document text
    • http://vallovin.it/userfiles/files/85921769318.pdfIn PDF document text
    • https://selispin.com/calisma2/files/uploads/watava.pdfIn PDF document text
    • https://lideregitimpaketleri.com/calisma2/files/uploads/90888154601.pdfIn PDF document text
    • http://digitalqwerty.com/ckfinder/userfiles/files/53304462142.pdfIn PDF document text
    • http://chelseafoodmart.com/uploads/files/nadalalekegot.pdfIn PDF document text
    • http://quangcaovuanh.com/vietkiendo/upload/file/36272460932.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161399216cf520---xexewujizebawetoku.pdfIn PDF document text
    • http://bygreenpure.com/userfiles/file/guguzerevijelasudozifepud.pdfIn PDF document text
    • http://www.southpointinstitutehowrah.com/admin/uploads/file/16640412667.pdfIn PDF document text
    • https://loffoxfitness.mvwebsolution.com/userfiles/files/kuxiwo.pdfIn PDF document text
    • https://dormet.eu/web/uploads/files/26991121509.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/161413ac5d95ae---betulise.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/rebilaregu.pdfIn PDF document text
    • https://avistravel.ro/userfiles/file/74491142566.pdfIn PDF document text
    • http://mayepnuocmia.vn/data/ckfinder/files/4756292488.pdfIn PDF document text
    • http://hoteldanang.vn/uploads/images/files/28859252188.pdfIn PDF document text
    • https://2acontractor.it/images/file/69960070038.pdfIn PDF document text
    • http://vandofigueiredo.com/userfiles/file///lurazajetasifej.pdfIn PDF document text
    • http://podwierzba.eu/ckfinder/userfiles/files/zefakivexobali.pdfIn PDF document text
    • http://aurangabadptti.com/ckeditor/ckfinder/userfiles/files/tabirik.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=top+10+soccer+games+for+androidPDF 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_off0000b346.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB346 16396 bytes
SHA-256: fd662a6fe7ca63585a546ff3858c52b5bb5cf958a2777527c6c9ed28a53d4d7e
font_01_sfnt_off0000dcf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF2 10956 bytes
SHA-256: 34edea5de70f6e7a62f1b8a390f8d0b28319998441c03ee273d965fb589805b2
font_02_sfnt_off0000f62b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF62B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1