Malicious PDF — malware analysis report

Static analysis result for SHA-256 e91c9d159f8ee7a2…

MALICIOUS

PDF

81.4 KB Created: 2021-09-18 12:50:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8e429fb7fae2a323358b7caf4f48a8a2 SHA-1: 87b748af893b48698d3fdf7d004b61370aa8ca90 SHA-256: e91c9d159f8ee7a2eb8872a08cf628024c1d3d6e557a8c4c574a4c7f7dd5c0d4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of links, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://www.juniorcollege.cl/ckfinder/userfiles/files/zetexuvanazipumafuwuw.pdf In PDF document text
    • http://midoriku.zaitakunet.jp/app/webroot/upload_images/files/80434659204.pdfIn PDF document text
    • http://heldermusic.nl/ckfinder/userfiles/files/11556900879.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/nabikafimijegopowiz.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/16289063692.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/3jod336k334mteu8ua6t3doqfp/kefiza.pdfIn PDF document text
    • https://dynasty888.com/image/files/20210904_010617.pdfIn PDF document text
    • https://egca.fr/userfiles/file/feduwigepi.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/dojunozajufinivum.pdfIn PDF document text
    • https://www.opsclown.it/ckfinder/userfiles/files/9361590734.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/1e7ad519f47697f7b52c772dd8eef199/gelomego.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210907154855.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/zumuse.pdfIn PDF document text
    • http://medizator.ru/ckfinder/userfiles/files/2251150950.pdfIn PDF document text
    • http://notar-frings.de/userfiles/file/gaxuzidut.pdfIn PDF document text
    • https://endobible.com/userfiles/file/17497122775.pdfIn PDF document text
    • https://semut73.com/contents/files/torufowagusenige.pdfIn PDF document text
    • https://uslugiinzynierskie.eu/eurostyl/photos/file/94805322049.pdfIn PDF document text
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/15597769812.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eefc85c883---gojonug.pdfIn PDF document text
    • http://quaint-house.com/images/blog/file/17229806811.pdfIn PDF document text
    • http://gurolmumcu.com/userfiles/file/delife.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+inspect+android+app+in+chromePDF 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_off0000d68a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68A 18644 bytes
SHA-256: 441caf2d15bcada4d96fb1a07094d2e54094ce0160e654b3e8ba8b81b73dda17
font_01_sfnt_off0001072d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1072D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F44 10808 bytes
SHA-256: b1d9cc3a5f8da593e4f0bcacb0c88883c6d22a8c85d7d08b1110af1fe0861061