Malicious PDF — malware analysis report

Static analysis result for SHA-256 872d56c3cd3b2efd…

MALICIOUS

PDF

85.9 KB Created: 2021-09-18 16:30:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 39934237631db1fdbd577c44dd5f0b0f SHA-1: 01bfd17a53edefbe9fcbf4fdc68b4aef603ae288 SHA-256: 872d56c3cd3b2efd29fe0890ac964f1bd678bd121fcaab544c7c8caeadbdf5a7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating a high likelihood of malicious intent. The heuristics 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' suggest the document is designed as a link farm pointing to compromised or disposable hosting, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript for redirection or obfuscation, hence T1059.007 is included.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://netflor.pl/upload/File/49149120115.pdf In PDF document text
    • https://olivier-daulte.com/ckfinder/userfiles/files/kesofaxuwisarewubub.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/6755253013.pdfIn PDF document text
    • http://it-hair.com/userfiles/6680811346.pdfIn PDF document text
    • http://kleni.cz/userfiles/file/polafeweseweguleliva.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/80791908727.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/6602030187.pdfIn PDF document text
    • http://kryotherapie.net/neu/userfiles/file/mojojisus.pdfIn PDF document text
    • http://aryajob.com/user_upload/file/nufavodovisep.pdfIn PDF document text
    • http://tunapvietnam.thietbiotoviet.com/Images_upload/files/sajimujodopupi.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-7/20210907095330176807.pdfIn PDF document text
    • https://datawire.gr/files/files/binowe.pdfIn PDF document text
    • http://casadiriposomarsala.it/userfiles/files/tajudafigugegutetukep.pdfIn PDF document text
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d0ced6385---36355515538.pdfIn PDF document text
    • http://tentimesneedlehill.com/UPFILE/userfiles/files/26614021735.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a14b80f5bc---34388051792.pdfIn PDF document text
    • http://imbirimbir.ru/files/jasadaser.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/da5b7b7449e5de0dc2703dae3580ba0e/mutadudinumit.pdfIn PDF document text
    • http://www.focitabor.hu/userfiles/file/dowimajafusimeloz.pdfIn PDF document text
    • http://technoprofile.ru/userfiles/file/nogojomisobevupipov.pdfIn PDF document text
    • http://nieruchomosci-swidnica.pl/userfiles/file/57388367264.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/pefujazeladolosewafine.pdfIn PDF document text
    • https://ketgate.eu/wp-content/plugins/super-forms/uploads/php/files/797d1e63527e484953147a86171e1503/nifuroxefiwetigejenefifag.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/0b8a8d572734a1c7f10b4af55ae5750b/64201487986.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=nexus+6+nougatPDF 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_off0000ec2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC2C 17784 bytes
SHA-256: bd48fa69ce3e0b9ac3f4549e3b4b0bc6cd84feff193e4c4572aa8e4cf05b7ea1
font_01_sfnt_off00011a51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A51 10392 bytes
SHA-256: b164a6f1d3a91cd9bae293faec26a2914c4b3831158715b84a587279d99fbb1f
font_02_sfnt_off0001321a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1321A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1