Malicious PDF — malware analysis report

Static analysis result for SHA-256 53f5cadebb8f00a3…

MALICIOUS

PDF

88.7 KB Created: 2021-08-06 09:26:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8900578e53963196c074d29f502f09f9 SHA-1: 8dfb9f7de9094d60e41d197d5a5515d53c4f9da0 SHA-256: 53f5cadebb8f00a3483e38efe4c82af1336d93083bf6010fdfd79fa9e919a362
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF containing embedded JavaScript, which is a common technique for malicious PDFs. It also contains numerous external URIs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • 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://jiehuist.com/userfiles/files/velezovumajileravasobup.pdf In PDF document text
    • https://ozsersogutma.com/upload/files/82465329155.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/9b29354f6c301a7c7ce1c4649b25ded8/44640250607.pdfIn PDF document text
    • http://rahwayhigh.com/clients/42761/File/dirigitomizujela.pdfIn PDF document text
    • http://www.associatedomains.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607726ce1be1c---jabat.pdfIn PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/fad6f17a5dbb85856ff00a47c0bd9bd0/zurure.pdfIn PDF document text
    • https://binarbaidrealestate.com/public_html/userfiles/file/furebuberobutiwire.pdfIn PDF document text
    • http://capitaloffice.pl/fotki/file/mukoma.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/7lp3s0eu35rk84r605gio01p1o/bavuzimo.pdfIn PDF document text
    • http://vanharteyoga.nl/uploads/files/67618939654.pdfIn PDF document text
    • https://maturana.cl/upload/file/bidumojuzonek.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160780dc34e4bb---57378842236.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608f790458a8d---vexiz.pdfIn PDF document text
    • https://senfina.top/uploads/files/sadevipavajitir.pdfIn PDF document text
    • http://iwish-cosmetics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c69991ba64b---vetetudewoxadopepo.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608762dd1b91d---lusibugutibutanawawive.pdfIn PDF document text
    • http://scuderia512.com/js/upload/files/guxek.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/160e97f1af133a---surovipatekasudarirodobot.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/9a11dcfe7c975e138b838f3cc2c5bfd3/1470194131.pdfIn PDF document text
    • https://www.straightmyteeth.eu/wp-content/plugins/super-forms/uploads/php/files/97f2e15fc8ff626cd9f03922d8e1e389/9853884038.pdfIn PDF document text
    • http://yesilderecine.com/admin/editor_resim/file/6785146700.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/10989463741.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=how+to+win+women%27s+heart+pdfPDF link annotation
    • https://medlineplus.gov/heartdiseaseinwomen.htmlIn PDF document text
    • 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_off0000f49e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF49E 17980 bytes
SHA-256: cc87ac3608b7f467c29e54b04c4beec56de261a4a43b2a504d5ca0df27584c5a
font_01_sfnt_off000123cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013be4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BE4 10828 bytes
SHA-256: a7d6af7a25c460240835aab94e1537f95b9194b4ddb2efdcffc27debe1af5994