Malicious PDF — malware analysis report

Static analysis result for SHA-256 f321335c323ea973…

MALICIOUS

PDF

85.7 KB Created: 2021-09-02 20:35:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 19752368e70dc88ff1b3e99257537116 SHA-1: 75340180407b31ceecce2a58dcf181cf61820d80 SHA-256: f321335c323ea9731a1a03718d3b774a56cb6a0e527307caced14c554d350234
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, forming a link farm. ClamAV and an ML classifier identified this PDF as malicious, specifically a phishing trojan. The primary attack pattern involves luring users through a malicious document to click on these links, which likely lead to further malicious content or exploits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://markasib.ru/ckfinder/userfiles/files/29223759648.pdf In PDF document text
    • https://www.harasportcenter.com/wp-content/plugins/super-forms/uploads/php/files/sssi5nt5ccb9kio36u4kf16fuo/varodojirowotekulu.pdfIn PDF document text
    • https://ludifrance.fr/userfiles/file/15234761414.pdfIn PDF document text
    • https://onecre.com/images/content/files/64138358123.pdfIn PDF document text
    • https://www.ltgpartners.com/wp-content/plugins/super-forms/uploads/php/files/adc746ac07856a4552a4fdccbe4cf701/46806562308.pdfIn PDF document text
    • https://plumcourse.com/wp-content/plugins/super-forms/uploads/php/files/ee8b6988b168e41ad9f8f58d780428e0/99789340059.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d343ea37ca---zujisekir.pdfIn PDF document text
    • https://zhavezbozi.cz/data/file/viziboborujixoweso.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160ab78f0afda3---58169416169.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/kufijoresaluzudi.pdfIn PDF document text
    • http://allaboutdowney.com/userimages/96315704827.pdfIn PDF document text
    • https://homeuu.biz/upload/ckeditor/pages/files/94755228392.pdfIn PDF document text
    • http://bhk-aindling.com/userfiles/files/72612361640.pdfIn PDF document text
    • https://israelonthehouse.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f12908c317---maxalufumuvepupozavofi.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/97711750033.pdfIn PDF document text
    • https://acronimocostanzo.com/userfiles/file/vejegitavijalaje.pdfIn PDF document text
    • https://pt2-turbo-j3t.com/contents/files/gomerujiva.pdfIn PDF document text
    • http://www.pvvc.cz/files/45797132809.pdfIn PDF document text
    • https://alihuata.com/userfiles/file/masujuxaguzolovop.pdfIn PDF document text
    • http://bfr-bialapodlaska.pl/userfiles/file/31556416489.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/22002239002.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/2118204098.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/pasefaritagad.pdfIn PDF document text
    • https://dobre-akce.cz/media/files/file/jofopefafaxudunilamer.pdfIn PDF document text
    • https://www.americansummercamps.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b7a3ac3f5---93647034096.pdfIn PDF document text
    • http://al-bandak.com/userfiles/file/62924235760.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=violencia+transgenero+pdfPDF 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_off0000e81a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE81A 10764 bytes
SHA-256: 9c1c617ac069ae32c043640c33ad7fb892c512c12a61088a3b794322380d9f23
font_01_sfnt_off000100ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100CA 19032 bytes
SHA-256: 9423b6fc7fd59e080e8e471f98716f06e982f7401a697377acf3ad0ab7a5e081
font_02_sfnt_off0001310f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1310F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1