Malicious PDF — malware analysis report

Static analysis result for SHA-256 43808c4f3d5605eb…

MALICIOUS

PDF

81.1 KB Created: 2021-09-19 14:44:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f3d321358ebf80cc9c281c095344b763 SHA-1: 3b756760a30e1a958ec4cf748c430e6010e65b4d SHA-256: 43808c4f3d5605eb048892ddffdb93f963751a601af9a3eb20a023d5180bcd9e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the links and the PDF structure suggest it's designed to exploit users by directing them to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://smidgel.ru/uplcv?utm_term=pixel+experience+k20 PDF link annotation
    • https://robert-zauer.cz/userfiles/file/taxexo.pdfIn PDF document text
    • https://prosaison.fr/userfiles/files/rizuwopejonesegulugugakix.pdfIn PDF document text
    • https://szalkasszorutacskok.hu/app/webroot/files/content/files/4016159942.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/41503393098.pdfIn PDF document text
    • https://nilsahost.com/calisma2/files/uploads/wonosedujej.pdfIn PDF document text
    • http://allier.proximeo.com/ckfinder/userfiles/files/juxefetuxedune.pdfIn PDF document text
    • http://lnv-cnc.com/userfiles/file/52546974685.pdfIn PDF document text
    • http://hoteldanang.com/uploads/images/files/69420793174.pdfIn PDF document text
    • http://dailythang.com/userfiles/files/kakipupabizuru.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/pemevisax.pdfIn PDF document text
    • https://thehideawayresortpattaya.com/userfiles/files/wudoferevesabojotijubed.pdfIn PDF document text
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/e1ffc7b0f70d6f09c2809f70c59de2a0/56884722377.pdfIn PDF document text
    • http://nuitsdartistes.eu/images/file/48951087060.pdfIn PDF document text
    • http://illinoislivestock.org/userfiles/file/bilexuzubopagaket.pdfIn PDF document text
    • http://erainbowrealty.com/userfiles/file/xanigitegesiriguk.pdfIn PDF document text
    • http://rracc.com/file_media/file_image/file/sozudalur.pdfIn PDF document text
    • https://manage4.realtourvision.com/rtv/ckfinder/userfiles/images/files/80067575762.pdfIn PDF document text
    • https://thegioidongphuc.net/ckfinder/userfiles/files/mokidaw.pdfIn PDF document text
    • http://smeeing.com/userfiles/files/14776809327.pdfIn PDF document text
    • https://mayphoviet.com/media/ftp/file/zejexokix.pdfIn PDF document text
    • https://listapp.in/ci/userfiles/files/10837110706.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16144b9fd67c0c---17025776415.pdfIn PDF document text
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/nc1m0cl0u40forj2iv0utrsalv/26988226790.pdfIn 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_off0000d778.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD778 18764 bytes
SHA-256: 131a4872dbd5c8444c95e8431b92b71322c99957b1e83c170841ffec5f1e72a8
font_01_sfnt_off000107e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107E2 10256 bytes
SHA-256: 8337a1f52aeadd4855822f9bf1a7141b3384ec15d178b98ef88a892a57b7379f
font_02_sfnt_off00011f0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F0D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1