Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5bfcdffc2396168…

MALICIOUS

PDF

93.3 KB Created: 2021-09-18 19:59:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7b436c408e92e3a23a1e383d01ebb23f SHA-1: afaad720b172e402b075947ff9b362301b4df05a SHA-256: d5bfcdffc23961682de0a773de2bb672e2c6adef81beb7936fa3f409cc53cdc3
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with many embedded URLs pointing to compromised CMS uploads and disposable hosting. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its malicious intent. The primary goal appears to be directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/csh2km4hdqseprg7809vc2a902/18590047500.pdf In PDF document text
    • http://strahovka66.ru/userfiles/file/16950379951.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/47203865139.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/d058212a7ea8bf1e45853711f0e3786d/jitetaxewuvotipikanoz.pdfIn PDF document text
    • http://bjallstar.com/upload/file/15991057621.pdfIn PDF document text
    • http://na3.it/misc/file/xebabifuku.pdfIn PDF document text
    • http://paroissedementon.fr/upload/files/5067163562.pdfIn PDF document text
    • https://glory-aqua.com/userfiles/file/86182865099.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/161426cf8beee9---robuvegujulepuzog.pdfIn PDF document text
    • http://ubestsports.com/imager/files/20210913221906.pdfIn PDF document text
    • https://vinniescustoms.com/userfiles/files/wikuxudupurudugowapale.pdfIn PDF document text
    • https://tipresentoio.it/images/file/pegeri.pdfIn PDF document text
    • https://a-1commercialkitchenservices.com/ckfinder/userfiles/files/11396256275.pdfIn PDF document text
    • http://kidneytracker.com/ckfinder/userfiles/files/tugajikome.pdfIn PDF document text
    • http://dalhousieretreat.com/cote_dor_import/admin/ckfinder/userfiles/files/dukedajizegojefozotu.pdfIn PDF document text
    • http://parbatsamajjapan.com/img/files/files/zekiwojal.pdfIn PDF document text
    • http://terralis.net/catalogue_dynamique/file/kovugar.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/29905404712.pdfIn PDF document text
    • http://multi-accueil.fr/ressource/site-image/files/43952813791.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/34004421150.pdfIn PDF document text
    • http://vatlieubaooncachnhiet.com/userfiles/file/8871438388.pdfIn PDF document text
    • http://electriccityusa.com/images/fck_uploads/file/37014162940.pdfIn PDF document text
    • https://ochronaskory.pl/pliki_user/File/38150631505.pdfIn PDF document text
    • http://tlumacz-bialystok.pl/pliki/file/79545272288.pdfIn PDF document text
    • http://fitviewer.biz/files/file/19776672629.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=here+i+am+jonathan+safran+foer+pdfPDF 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_off0001043a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C51 10836 bytes
SHA-256: 1dd69e784e7f9e0d81ab430e7fdba6c1156bd543fcd494b9192d306b240f255e
font_02_sfnt_off00013507.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13507 19524 bytes
SHA-256: 68f502a9fe2b61d9b99739970800594ef8eac0df47eb5c53627a551ec8400ff4