Malicious PDF — malware analysis report

Static analysis result for SHA-256 78cce107c7ab9794…

MALICIOUS

PDF

123.6 KB Created: 2021-08-14 22:25:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e4ce3593fd082b8f3fbf24421784a51c SHA-1: e4e6a2abc368c8c3d8429e07dd805ebc38fbdd85 SHA-256: 78cce107c7ab979440c6e7fff709a1bf907ed8394b74cf27eea3e453d358a750
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories. The ML classifier strongly indicated maliciousness. The document body is heavily obfuscated and unreadable, suggesting it's not intended for human consumption but rather as a vehicle for these links. The primary function appears to be redirecting users to potentially malicious content hosted on compromised websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/9986677d240410c0eb13cc253de0bf4c/jowerowalimimoxi.pdf In PDF document text
    • http://teormech.ru/teormech/usrimg/file/perixagejosesisefi.pdfIn PDF document text
    • https://laser-arena.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607288663f473---kosile.pdfIn PDF document text
    • https://worldmedglobal.com/userfiles/files/zebis.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/boxilupilaba.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160754cc46d690---dikomepoluva.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/16075fece7ec58---malanutofozuxuziraxibobo.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/6977dd94823ee97f7f8fede8c7aece86/43819488097.pdfIn PDF document text
    • https://pharma-tools.eu/galeria/file/32779038077.pdfIn PDF document text
    • http://www.satunatc.ac.th/ckfinder/userfiles/files/xiwutupakomo.pdfIn PDF document text
    • https://rrr71.ru/upload_picture/duriravesuloxuxanibizu.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16113f009a4394---63294070522.pdfIn PDF document text
    • http://klasykarozrywki.pl/public/images/fck/file/rabuzisin.pdfIn PDF document text
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/a3629211e1d4dc0e070f72ff83107d14/bibutogetukexapozotor.pdfIn PDF document text
    • https://santa.my/images/users/00000000/files/gunugesowetop.pdfIn PDF document text
    • https://aviseco.ro/userfiles/file/nuvadatidiwatezidos.pdfIn PDF document text
    • http://centrons.com/uploaded/file/82245511360e249bd86667.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160e676d6df67c---56521433620.pdfIn PDF document text
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/nlu5dqf1slp55pdo69sjipe4pm/31482041894.pdfIn PDF document text
    • http://wernitznigg.at/files/50703576867.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/kk2gb96i7es6fjc51kmohpcqt6/41744311134.pdfIn PDF document text
    • http://nessium.net/userfiles/file/nofuxatirunirivorare.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=hielos+perpetuos+clima+flora+fauna+y+ubicacionPDF 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_off00017b12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17B12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00019329.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19329 10984 bytes
SHA-256: c744939af4f490c2370e6b11e89fac630f112e7365b995929271734955bd1c06
font_02_sfnt_off0001ac7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AC7A 19676 bytes
SHA-256: 4ff8495db6f322fec69f2b4997a44085e74b14aff5c8161f0caa0f1c1bfdb3d0