Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1a57b93ec5efa77…

MALICIOUS

PDF

70.1 KB Created: 2021-09-28 07:25:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 88be6cc7adfcd51f93ea2724dd6819e3 SHA-1: 6f3abd937e1d99ab43840235137a7c4f59b2469c SHA-256: f1a57b93ec5efa778b23b10c3b5e4dcda12935d2edf5099e4d984f6940c23660
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files, many hosted on compromised CMS sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of multiple external URIs and a link farm heuristic confirms the document's purpose is to redirect users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://strategieb2b.com/userfiles/file/durugagetolu.pdf In PDF document text
    • https://ncltandatbar.com/home/ncltandat/public_html/dowalumniusa/ckfinder/userfiles/files/72957135297.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/0ad0ec0f325d02db946979196d3dd99c/59931328869.pdfIn PDF document text
    • http://indianmailbox.com/assets/images/userfiles/files/tuxogukiso.pdfIn PDF document text
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/8323235066.pdfIn PDF document text
    • http://multiflex.ru/userfiles/file/73655465973.pdfIn PDF document text
    • https://sapporomn.com/userfiles/files/73156117391.pdfIn PDF document text
    • https://fanaf.com/article_ressources/file/junedorisifawufosez.pdfIn PDF document text
    • http://wenyanchem.com/upload/files/xiperodizupamoxib.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/20080755064.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe58f286df---84784155255.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/42372117986.pdfIn PDF document text
    • http://zivotzaokny.eu/res/file/16474515855.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/xelunidaladizigeberadi.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614235e48a159---gipuketegegasafelix.pdfIn PDF document text
    • https://5a.ro/ckfinder/userfiles/files/84627174124.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/92f7f685bf257ee90dd8c80f508101e5/vonuzaradi.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/52950403072.pdfIn PDF document text
    • http://genarchi.com/data/temp/file/81363372841.pdfIn PDF document text
    • http://ecolservizinettuno.com/userfiles/files/25022740612.pdfIn PDF document text
    • https://transport.frontiermyanmar.com/sites/all/libraries/ckfinder/userfiles/files/zabofowu.pdfIn PDF document text
    • http://webcertain.net/contentupload/fckeditorUploads/organization_/file/vesaremofakijusaginiku.pdfIn PDF document text
    • https://gulceoyunlar.com/calisma2/files/uploads/lagolofuno.pdfIn PDF document text
    • http://stacjaregeneracja.pl/userfiles/file/2388883976.pdfIn PDF document text
    • http://asirakademi.com/resimler/files/sitajegeberomujevowul.pdfIn PDF document text
    • https://saikekanglun.com/filespath/files/20210905065351.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=shareit+apk+newPDF 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_off0000b4d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4D7 15124 bytes
SHA-256: 24a1c143a84d5f557edc8d355990daae94a850394620d903dacfa3f208ad6e6a
font_01_sfnt_off0000db5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB5C 10268 bytes
SHA-256: 5985aea8b9fe0bf8c7db857adbd4dde8b4d52424dbda0052189a6db200f896f7
font_02_sfnt_off0000f27e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF27E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1