Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a66c34e631e0476…

MALICIOUS

PDF

146.6 KB Created: 2021-07-03 06:24:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 2d4a32da60a0e448d9c2caeedfa8f0fc SHA-1: b8651d9aab2870f556f957788684b585f8b130b0 SHA-256: 5a66c34e631e047655a7965e41731f2528cd43d7544f1cd8b8e6b6f090a258e2
224 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous links to external URLs, many of which point to compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The embedded JavaScript and link farm suggest an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9756

Heuristics 9

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://wastran.ru/uplcv?utm_term=easter+monday+holiday+2021 PDF link annotation
    • https://www.rockfallco.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607252f6c2ac6---filisimavipawonosubebej.pdfIn PDF document text
    • https://hansenlight.com/UploadFile/files/nimuxuvabujavixupu.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/21725763737.pdfIn PDF document text
    • http://stkvn.ru/wp-content/plugins/super-forms/uploads/php/files/47fbec7a0d9b97aa98f99b0bbe7922e4/84763515036.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/160b3a24bb9e43---tanizekozoxisinigaxodimew.pdfIn PDF document text
    • http://chromavials.com/d/files/13530843045.pdfIn PDF document text
    • https://myphambambi.com/webroot/img/files/8580597442.pdfIn PDF document text
    • https://dcmheavyequipment.com/admin/images/file/55848680929.pdfIn PDF document text
    • https://www.helmmsp.ca/wp-content/plugins/super-forms/uploads/php/files/a21be7395aaecf8e600887f5ba3ea358/50165737581.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/jufisige.pdfIn PDF document text
    • https://adbetelparaguay.com/wp-content/plugins/super-forms/uploads/php/files/70cf7ebb9990dd40e35bd0fb0e3fe264/gilidon.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/9381f76fab8833b922d025ced0317bf0/divipidepugo.pdfIn PDF document text
    • http://artistalexanderkanevskywinnerinternationalaward.com/clientMedia/file/48314126484.pdfIn PDF document text
    • http://agendaalzheimer.org/files/galeria/files/pijimin.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/xudubo.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/eah16if11kulplripdq8go9rqb/29423196587.pdfIn PDF document text
    • http://www.finanzanlagen-honorarberatung.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b736af50761---nuviwawe.pdfIn PDF document text
    • http://icltindia.in/userfiles/file/17385297721.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b063be3df76---fesalabaziwizanokaruxatox.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/2cfbc832502361a2f22454cec3aae2c7/18428562944.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1607fff18e6a3d---57034647082.pdfIn PDF document text
    • https://thesmithgrouphouston.com/wp-content/plugins/super-forms/uploads/php/files/360c23ff7318f533dcfa79debd396271/mikaxutuwopozivururovi.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/85785089818.pdfIn PDF document text
    • https://medicinasolidale.org/wp-content/plugins/super-forms/uploads/php/files/75ac6131ba848f89d5e806b7ecf26423/kaxex.pdfIn PDF document text
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001b609.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B609 24932 bytes
SHA-256: 9eee5551a24fc46924c7721d87c9f4e97932fed15036438f4a67072d52e27e7e
font_01_sfnt_off0001f353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F353 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00020b64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x20B64 16692 bytes
SHA-256: 458fd5205e92a716797fcdb65c2bae78a63634f94c10db0aced27faacfe32446
font_03_sfnt_off00022329.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x22329 10904 bytes
SHA-256: 974a840cc5623d6ef8ccbccd877b517ddf8c34f1986814684ded47317dbb2e68