Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc6b11b937bb86ba…

MALICIOUS

PDF

94.9 KB Created: 2021-06-27 16:10:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 5d50b73e188515bd46af76a17c1fde84 SHA-1: f1a426742c616a216cd4ca7537826fea2f180b76 SHA-256: dc6b11b937bb86ba48b0e39be829b30d6d60a07b2cfd129b0742119fd2933418
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous unknown PDF files hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristics and URLs suggest a redirection scheme to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://3duct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfaa3d2a6c---jeteriruxademi.pdf In PDF document text
    • http://vietsonplastic.com/uploads/userfiles/file/dikipowivafanugigu.pdfIn PDF document text
    • https://airbays.com/userfiles/file/pibusage.pdfIn PDF document text
    • https://bancodevida.com/bancodevida/admin/images/image/file/dulozufojazudaxaviw.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/1448515460.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607436d7df12c---vixuwodise.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/cf33f02e7614e4aecf5bda96b32c2866/mebir.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/fasawoxagalok.pdfIn PDF document text
    • http://dush-kz.ru/uploads/fck/file/88285684989.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160c0cafb7330a---63076445710.pdfIn PDF document text
    • http://granitemountainranch.net/userimages/46260005902.pdfIn PDF document text
    • http://creativeindustries.ru/uploads/userfiles/file/99211028385.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160985c475934d---wobezebakoxopegupesifuzo.pdfIn PDF document text
    • http://holidayinntorino.com/userfiles/files/naririzugud.pdfIn PDF document text
    • https://www.stjohnhomelessshelter.org/wp-content/plugins/super-forms/uploads/php/files/dd384621da8db59cea6da6c0cf05114b/modugunasokogetesoxu.pdfIn PDF document text
    • https://syntellect.ru/Repository/file/62173593955.pdfIn PDF document text
    • https://alrukn.co/userfiles/files/fexojiduv.pdfIn PDF document text
    • https://agmatbaa.com/upload/files/malotevebotavolevovejozuv.pdfIn PDF document text
    • https://cplastik.com/data/cms/file/72483286833.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b2a7c0f0471---6922866436.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d91f79fd5e---joseforisugog.pdfIn PDF document text
    • http://www.lightingandhvacexpo.com/wp-content/plugins/super-forms/uploads/php/files/b8f9c03b3219b47aad49b5ccd5423951/6173605106.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/30485882717.pdfIn PDF document text
    • https://wrd13.com/force/file/25672955647.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=the+trials+of+brother+jero+free+pdf+downloadPDF 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_off0000f866.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF866 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001107d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1107D 10912 bytes
SHA-256: 6b546d6e2064a12a9936d8563ec7a08243ec5b4ffb4330bddf379d62ace15e49
font_02_sfnt_off00012975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12975 16280 bytes
SHA-256: 5156ddcd44482fcd10f29113354d7625e56ff09c810cc0857abf09acc13150e7
font_03_sfnt_off00013f4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F4F 17720 bytes
SHA-256: 862245d9bdcdeed1b774816a18580b5e0b934091f1d472b57da2c1f2f49df446