Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4fc5f2f3e503d17…

MALICIOUS

PDF

94.8 KB Created: 2021-06-13 18:00:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: a2313deeceb0f716f8658a9df89729b8 SHA-1: cd0012dc703f112fdba378360ef495af37641dd1 SHA-256: a4fc5f2f3e503d1716321b8b1b92660b724f2fd20670bd925749681b5d69b916
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF document contains a link farm pointing to multiple compromised WordPress sites, disguised as a software download. The presence of numerous external URIs and the ML classifier's high confidence score indicate malicious intent. The document body, though heavily obfuscated, contains references to 'itunes 12.1 3 64 bit download', suggesting a lure for software downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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 https://krisoc.ru/uplcv?utm_term=itunes+12.1+3+64+bit+download PDF link annotation
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/16094295bc0d32---savisuzesuzojewuro.pdfIn PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1608451266bc54---689991369.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc740015e4a---67534597083.pdfIn PDF document text
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a210c318694---77783773886.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/b8d39844054690cb7f5698f6c5e7f9b9/77374021830.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160774bab585fa---mozuwurelotolamaja.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb2db060a6---vebevarolev.pdfIn PDF document text
    • http://ecompletecontact.com/ckfinder/userfiles/files/71475951497.pdfIn PDF document text
    • http://www.adatechotomasyon.net/wp-content/plugins/formcraft/file-upload/server/content/files/16088a7d2f031b---pitapusagojen.pdfIn PDF document text
    • https://kham.vn/userfiles/file/menoxonemuzafakor.pdfIn PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad207b98a64---6649107744.pdfIn PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609127252b390---pixopatagubigovirit.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/5d0d8a5d8d56e4dbe89c02f8e91164c4/37462386891.pdfIn PDF document text
    • https://tractorpulling-emmeloord.nl/upload/file/riwuruxufoposew.pdfIn PDF document text
    • http://novussiteyonetimi.com/uploads/file/81730655352.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608968a95fd4b---netofowufozipigezo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn 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://scripts.sil.org/OFLIn PDF document text
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000efc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC9 5684 bytes
SHA-256: 183ecf902187dd46b8ae61cd4d6049d12610c4b7d2726ff7be95b12fcfb5f6fd
font_01_sfnt_off000103a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103A4 5516 bytes
SHA-256: 9cd51a9fc48b3f9017986c1ac93488d225a03f0cf796d8a8e617536a1cdee112
font_02_sfnt_off00011685.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11685 6148 bytes
SHA-256: 4910d0177da9f60ecc92c13a34fae8c5c38ffafb9e4e22a3c3fd987548b79157
font_03_sfnt_off00012666.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12666 14900 bytes
SHA-256: 36ce3fbc6a6f1f20610ced0abdb83455e2079a1313b354310149c3a8957a77b1
font_04_sfnt_off000152de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x152DE 16984 bytes
SHA-256: ecc63509b2433281df26660924ac08c475afdcbed26f7717632b5d9a5cf7442f