Malicious PDF — malware analysis report

Static analysis result for SHA-256 f797c728e966e52f…

MALICIOUS

PDF

70.2 KB Created: 2021-09-29 08:06:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: b386c2f03e14802796fccda595f34b1b SHA-1: 7b0a782eeeda8ead5489c09ef9b8572e6c3b27c3 SHA-256: f797c728e966e52f551dabe52b1e406cd7f2ddb282553865f81930ccf71b6c7a
156 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and unreadable, providing no direct textual clues.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://nickels.design/ckfinder/userfiles/files/11365301174.pdf In PDF document text
    • http://emblem4home.com/UserFiles/Member/File/nutew.pdfIn PDF document text
    • http://laibros.com/ckeditor/userfiles/files/28901383854.pdfIn PDF document text
    • https://mimpiindah168.com/contents/files/3333159764.pdfIn PDF document text
    • https://euro-m.si/web/dokumenti/file/mikurimizu.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/od84tg2s8m1tnd6jc2skos81kv/golapexunaxujeditup.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data/files/retemenefujixinuso.pdfIn PDF document text
    • http://simpelms.nl/userfiles/files/mugorazulofawavel.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/f4dfb0f223ff67610b35087112b11063/vagusomexedunozusat.pdfIn PDF document text
    • http://scsytech.com/upload/files/safovulikujawo.pdfIn PDF document text
    • http://fincasotilloviejo.es/files/sotillo/_repo/file/kejazikorizopekapobexal.pdfIn PDF document text
    • https://vanphongphamhienluong.com/upload/files/305994261.pdfIn PDF document text
    • http://mxm-hosting.nl/img/editor/file/lotolevaxobikurulovidom.pdfIn PDF document text
    • http://alfamar.travelshops.pl/userfiles/file/jadibafegisibikuk.pdfIn PDF document text
    • http://eaas-journal.org/survey/userfiles/files/kedupa.pdfIn PDF document text
    • https://skykharchono.mn/editor/files/17774300312.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/16904359505.pdfIn PDF document text
    • http://diskacme.dk/images/upload/file/sujoxiwuxanujidemebu.pdfIn PDF document text
    • http://bargiel.com.pl/ckfinder/userfiles/files/wagusizomorabep.pdfIn PDF document text
    • http://sellmysayarah.com/userfiles/files/26777934738.pdfIn PDF document text
    • http://gurolmumcu.com/userfiles/file/31250086343.pdfIn PDF document text
    • http://nage-z.com/ckfinder/userfiles/files/turokodovarur.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/6af9de9cee832fa04fd63b38ff838387/febiv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=apk+only+free+firePDF 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_off0000b26b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB26B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA82 10108 bytes
SHA-256: e4bcf354ecba92b47d3e8a6b66d08e1e780088ed8e3eaaf4954f0126dafb0c1d
font_02_sfnt_off0000e129.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE129 16464 bytes
SHA-256: a8c1fa50ccb45d2f2f00e361c881181eb53a8cf1ac62f5ad614d9b6df0472ba6