Malicious PDF — malware analysis report

Static analysis result for SHA-256 b33ac978102e1b9f…

MALICIOUS

PDF

94.7 KB Created: 2021-07-19 05:30:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 996d12607c7d91022ffdb4fadb23176a SHA-1: 9990b5a8c78be7665fe6d6c2aa71d524d144f315 SHA-256: b33ac978102e1b9f790a4209026a1c28447c384b7c473b68c51d790141cd7a5a
156 Risk Score

Malware Insights

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

The file is a PDF identified as malicious by ML classifiers and ClamAV. It functions as a link farm, containing numerous URLs pointing to compromised WordPress upload directories and other potentially disposable hosting. These links likely serve as lures for phishing attacks or to distribute further malware. The ML classifier's high confidence score and the nature of the embedded links strongly suggest a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://hotel-la-licorne.fr/userfiles/file/93461545826.pdf In PDF document text
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/9f980e69f27714816f322b6a86b8851f/13797277125.pdfIn PDF document text
    • http://kcde.kr/userfiles/file/jokitosegolefojem.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/k2sn431vtu0hj3k1bd22me3si5/sazixibotawazetazakazif.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160862b458dd9e---kufilabam.pdfIn PDF document text
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/48f5f3f7971ed7ca31aa5e8662d4a8da/faxedore.pdfIn PDF document text
    • https://warungmimpishio.com/contents//files/sogepusifanapu.pdfIn PDF document text
    • https://mangonebike.com/uploads/file/memoguvunepilukunutasi.pdfIn PDF document text
    • http://debandhelder.nl/ckfinder/userfiles/files/jadanijefevob.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160716597ae49c---35125341544.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/0edf92fb16029b38a5d4335857b4a48e/zesaxakulinexikuworiruxe.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/31d15d591c44d8d48773aabf2d2725a9/26105060400.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/16078408c14e8d---dubelavawisevuporaz.pdfIn PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608a5838b60a3---fewatiniwibebenidulazo.pdfIn PDF document text
    • http://www.climatisur.com/ckfinder/userfiles/files/xiwodekenuzubunujefok.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/munomenenilomimuzizodasab.pdfIn PDF document text
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16074b9862e62b---xananar.pdfIn PDF document text
    • http://tele-video.ru/upload/files/suluz.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/memirap.pdfIn PDF document text
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/bae85fa93fc88a42cdc1e13b3e2e89f7/69999250686.pdfIn PDF document text
    • https://robinio.de/wp-content/plugins/super-forms/uploads/php/files/17jti2v6j30mg7n06ahpqsa3ar/mujujodikopegavuk.pdfIn PDF document text
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/ee13da4b1bca9bead5ccc5eda480de17/fepubigij.pdfIn PDF document text
    • https://divetechmarine.com/contents/files/52149416169.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=what+does+salient+mean+in+psychologyPDF 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_off00010a45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A45 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001225c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1225C 10968 bytes
SHA-256: 74e65a8e6fa676e1045ad7fd3761d2c79ba1471a290513bcd14a53c6a2844cc5
font_02_sfnt_off00013b6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B6B 19540 bytes
SHA-256: aff77978a7a8014068db0abdcb4206f132416c964065a96f3c9bd3f98e0308e3