Malicious PDF — malware analysis report

Static analysis result for SHA-256 21b38145a06d8382…

MALICIOUS

PDF

85.3 KB Created: 2021-07-20 00:45:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 974a12fbe2da3c3059aba53cbb0c033f SHA-1: 96db24e1ef95f35ea36b0018794c0e2d833af67a SHA-256: 21b38145a06d8382bdfb81e5b50eab0d6d5662a3fb252bec8844594fb5485246
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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 https://www.kunapak.com/wp-content/plugins/super-forms/uploads/php/files/5ponhibd3tqdu1s3drjb6c6hkc/29848797747.pdf In PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/f1747f4593a004a1a10fa446f5c61fc3/baxexezinopa.pdfIn PDF document text
    • http://fecirturizm.com/resimler/files/fapupuj.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0f98059281---vuvuwodi.pdfIn PDF document text
    • http://hotelamadeustorino.com/userfiles/files/93172879535.pdfIn PDF document text
    • http://tetraeng.it/userfiles/files/47270226618.pdfIn PDF document text
    • https://everywheregenes.com/uploadfile/qu26_qu106_com/files/napagomudojomologa.pdfIn PDF document text
    • http://bezpieczna-strefa.pl/wp-content/plugins/super-forms/uploads/php/files/e17f95e9bb0a3eec39b47847f38d35ec/sitinomigetekabolumi.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f56886d5f3c---28676298693.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16084a615349db---46440205415.pdfIn PDF document text
    • http://ledson.ru/upload_picture/88780881748.pdfIn PDF document text
    • http://pneusmarene.it/images/file/kuvosoregixalujevuxowa.pdfIn PDF document text
    • https://deitratech.com/userfiles/file/sozidag.pdfIn PDF document text
    • https://www.emma-solutions.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a9d0707bb17---72341316950.pdfIn PDF document text
    • http://aryajob.com/user_upload/file/vafotofubowi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+get+lcm+using+prime+factorizationPDF 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_off0000e8ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8EA 11060 bytes
SHA-256: c3b97bf60cedfe1abe5ade21dc1e37a483e1b8f7052c81c5c4f6476a983b58f3
font_01_sfnt_off000102b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102B8 17372 bytes
SHA-256: 05287c95ff67b175c238074ac2f3e72b1e1d8f249fc007ed9100c705672f69c1
font_02_sfnt_off00013082.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13082 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1