Malicious PDF — malware analysis report

Static analysis result for SHA-256 da583c78cba61977…

MALICIOUS

PDF

82.7 KB Created: 2021-09-11 23:45:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 9efefdf7b73934882b03a5192d5e9e2c SHA-1: eaff53846f69c6ce7cc32ed431df5d8e8d5e1f80 SHA-256: da583c78cba61977903ac68dbe0d86cc40e9b75b013b9115561d07522f8b9e5e
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting an attempt to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is heavily obfuscated and does not provide direct clues, but the presence of multiple external links and the high heuristic scores point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://myucpb.net/userfiles/file/fajobadokib.pdf In PDF document text
    • https://bda.ch/ckfinder/userfiles/files/60046976737.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/19049606054.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c37aa44d7b---dulax.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/32668742629.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/37189599550.pdfIn PDF document text
    • http://tuanlongland.com/upload/files/peraxaxelaj.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/d35f352ba7a85bd3595ab8aeae35d2b5/tulinedona.pdfIn PDF document text
    • https://il-gusto.com/images/file/12820584062.pdfIn PDF document text
    • http://fujavietnam.com/images/Download/rarokofifulozup.pdfIn PDF document text
    • http://domki-kopalino.pl/pliki/rofuvetafopewa.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/dovakozapujugesedujid.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/sebawa.pdfIn PDF document text
    • https://xuanhongkhang.com/upload/files/kuvubogijumuxowesefugulo.pdfIn PDF document text
    • http://kwiatmetal.pl/userfiles/file/7584419752.pdfIn PDF document text
    • http://naturalfurnish.com/userfiles/file/71324406220.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/wejanafosivuvibaxonevi.pdfIn PDF document text
    • http://5percent-design-action.com/upload/users/files/galewenibok.pdfIn PDF document text
    • https://hylyt.co/wp-content/plugins/super-forms/uploads/php/files/0696aceb77dd78842f07c4575896213d/11097575614.pdfIn PDF document text
    • http://binhchuachay.info/Images_upload/files/98364876486.pdfIn PDF document text
    • http://www.terresdescaraibes.fr/file/fupidamifutuvemiv.pdfIn PDF document text
    • http://regmac.net/userfiles/files/todowenorelinefitatujune.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613bea6d97655---bokefijexuri.pdfIn PDF document text
    • https://cosmopolitanhotelbg.lastrada.bg/uploads/wysiwyg/files/dozifebada.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/tupufotokixinu.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/17283232807.pdfIn PDF document text
    • https://stancijanegrin.com/UserFiles/files/banemisabe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=old+imo+app+downloadPDF 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_off0000e09c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE09C 10168 bytes
SHA-256: ca7ffe42aca6511f423c2173534437997e9f24d64e1c1b95e037f847099403b1
font_01_sfnt_off0000f743.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF743 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F55 17872 bytes
SHA-256: 204f8d38d8054b36894694c3543f9d6957a2b3ce017c5f5f0296f5936ffdaa72