Malicious PDF — malware analysis report

Static analysis result for SHA-256 0aff5f687fb137de…

MALICIOUS

PDF

76.0 KB Created: 2021-09-15 13:45:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0012d026de05ba3fc693bdb4e0ae652d SHA-1: 64c28a814701a73d0d4a2645fa5500346bb5bc9a SHA-256: 0aff5f687fb137de7e2be5def2c8e3b250a520d96a57ae4f4351c94daf078af8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which are disguised as PDF files on various domains, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating a pattern of hosting many links on disposable domains. While no scripts were explicitly extracted, the structure and URL patterns point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://ecoquimica.cl/dinamicos/uploads/file/vekutidi.pdf In PDF document text
    • https://3drm.bg/uploads/pictures/files/27212108499.pdfIn PDF document text
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/vejuwolusakopitememug.pdfIn PDF document text
    • https://lexcyberia.com/userfiles/files/venikesovofosito.pdfIn PDF document text
    • https://culturasiapamplona.com/guiarte_userfiles/files/24257470112.pdfIn PDF document text
    • http://benetalent.com/upload/files/lagobutukipogeketimo.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/newujet.pdfIn PDF document text
    • https://crbz.ru/userfiles/file/menawumijul.pdfIn PDF document text
    • https://red-adlay.com/upload/files/funijulolinojud.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/27317529190.pdfIn PDF document text
    • https://rubyyadav.com/nbloom/fckuploads/file/69316671456.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/lelowimiwuvisidajesodemu.pdfIn PDF document text
    • http://baltyk.recykling-rejs.pl/imgturysta/files/1239976192.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16141b25db812b---gadezake.pdfIn PDF document text
    • http://mega-stainlesssteel.com/uploads/image/files/zimodadujirorijo.pdfIn PDF document text
    • http://khocabien.com/uploads/files/nukazokifakatoxamukotome.pdfIn PDF document text
    • https://www.auto-ecole-acm.com/ckfinder/userfiles/files/jekesedanomewi.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa25f97260---rijonudo.pdfIn PDF document text
    • http://kwong-cheong.com/userfiles/zidaximimij.pdfIn PDF document text
    • https://pellevah.com/upload/files/gitakujiwemabuxexobuxiti.pdfIn PDF document text
    • https://jpjplumbingandheating.com/FCKeditor/file/5164480092.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/fokiladavo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=pdf+unlock+to+copyPDF 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_off0000c6ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6EA 17368 bytes
SHA-256: 28d31f2dcd99ba9223aa5e38ab0c064daa612d8fae3dd7934f9e904564175ea7
font_01_sfnt_off0000f393.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF393 10268 bytes
SHA-256: c9a606f0f353c8286ae39a53986f044e8d129422e93b328152fc369aceb26cca
font_02_sfnt_off00010ad3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1