Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4b6cb94f60a44d7…

MALICIOUS

PDF

71.3 KB Created: 2021-09-19 18:54:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8d963cad4edabcecea1512c57a684f9f SHA-1: 1b10c40413e18dfa07e556781f9e2d75336f9658 SHA-256: f4b6cb94f60a44d75a0af6de902734a918d428a18727e42833eca09c5df6de00
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm pointing to various PDF files hosted on compromised websites and disposable domains, masquerading as software downloads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were directly extracted, the structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 6

  • 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.
  • 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://coming-c.com/userfiles/file/23335172910.pdf In PDF document text
    • http://bancasemecanino.com/userfiles/files/95315491810.pdfIn PDF document text
    • https://idd.no/ckfinder/userfiles/files/64330621291.pdfIn PDF document text
    • http://polesprogettazioni.com/userfiles/files/98665274053.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/16141ae4a1b30d---subizumolo.pdfIn PDF document text
    • http://palami.by/images/file/xulolipuxuzevuxuboguv.pdfIn PDF document text
    • https://vinocastillo.hu/editor_up/84242037153.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/muzemu.pdfIn PDF document text
    • http://ocung.net/img/files/rebemoneritabubo.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613034a40a7b1---gasuriwiwaridibovoz.pdfIn PDF document text
    • http://galenbio.com/images/upload/file/92984514998.pdfIn PDF document text
    • http://hanyangsteel.com/files/fckeditor/file/187843203661333931947af.pdfIn PDF document text
    • https://sainaudit.mn/File/xeledu.pdfIn PDF document text
    • http://373113.linker.tw/files/kutisikat.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8eac96272---nubexolodoxu.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/muvoripumisifadamek.pdfIn PDF document text
    • https://giant-nano.com/app/webroot/userfiles/files/wijuwodawumedolejaxoki.pdfIn PDF document text
    • http://nyett.hk/uploads/news/files/64170325545.pdfIn PDF document text
    • http://anhhieu.vn/hinhanh/file/xegelo.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/facad21bbb7391a2d0be084ba54367cf/91750377045.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142f241c972d.pdfIn PDF document text
    • http://eko-baby.ru/userfiles/file/63467982510.pdfIn PDF document text
    • http://flashdisplay.net/UploadFiles/FCKeditor/20210916042013.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=minecraft+pe+free+download+ios+no+jailbreak+2020PDF 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_off0000b343.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB343 11296 bytes
SHA-256: f8dcb7f54b0e8516a33602ea4a0907e90b2d6308d127d46c2cb0482002f3b9e2
font_01_sfnt_off0000cdc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDC4 16460 bytes
SHA-256: 0b818697cd7b782ea57dfce89a71283b13e264b70671897db556ab399b6de556
font_02_sfnt_off0000f786.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF786 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1