Malicious PDF — malware analysis report

Static analysis result for SHA-256 82935677a6ff66b1…

MALICIOUS

PDF

87.9 KB Created: 2021-10-15 07:26:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: bc344e39ba895c1baea575edddd6a016 SHA-1: 781770bc1302d5978922c91158860a05980004da SHA-256: 82935677a6ff66b1f8acc425e77db6ea2394b816b8c936bebad84ad8140505e6
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by an ML classifier as malicious and contains numerous links to external websites, many hosted on domains identified as compromised CMS uploads or disposable hosting. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather to host these links. The presence of multiple links to potentially malicious or compromised sites indicates an attempt to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://gorod-r.com/userfiles/file/xijaki.pdf In PDF document text
    • https://muguet.fr/sites/default/files/file/41047426241.pdfIn PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/16502940866.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/a112cce28a30dfd0464f55c818264a2a/7906140059.pdfIn PDF document text
    • http://usateatop.com/_upload/files/2619150356.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210919121701.pdfIn PDF document text
    • https://goodline.by/userfiles/file/35192739771.pdfIn PDF document text
    • http://naturallabs.de/userfiles/file/69496682249.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210920032322145964.pdfIn PDF document text
    • https://bunianco.com/other_files/File/47580825902.pdfIn PDF document text
    • http://laarakkers.com/ckfinder/userfiles/files/riresotedelegorezol.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/ddf5efc610a27bfeadce84a75adb2aac/bakajipetufeso.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/489168089.pdfIn PDF document text
    • http://aprt1day.ru/file/galosure.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/12005870454.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da65d724cd---pixebogoxomutegivawofove.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133b30f032cf---kajatubekuri.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2adfe2e19---zoluraladadaxomok.pdfIn PDF document text
    • http://em-mould.com/ckfinder/userfiles/files/fupiwewanumamupuza.pdfIn PDF document text
    • http://bpsstudio.hu/uploads/satunaxum.pdfIn PDF document text
    • http://magnumprint.ru/upload/files/75496952813.pdfIn PDF document text
    • http://bagumul.com/file_upload/spaw_upload/file/20210916235441.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4163af66b8c314e0157754ae9994e004/xuvijojezuxuvilugeg.pdfIn PDF document text
    • http://davobio.com/upload/files/rixifosemivigadaju.pdfIn PDF document text
    • http://medicapoland.pl/uploaded/file/21103691886.pdfIn PDF document text
    • http://feedproxy.google.com/~r/MbOu/~3/EqozwcbAC44/uplcv?utm_term=any+two+mathematicianPDF 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_off0000f483.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF483 17728 bytes
SHA-256: 12ea50d2420282ece7708ca7435ee0682a16820b9ebfdf6acdd1de70e0576821
font_01_sfnt_off0001229b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1229B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AB2 10364 bytes
SHA-256: e48e3772514884772bb73fa0bab81f432b24a0a0a0d20e1b1d4a6eb60e854530