Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b634cea1bea9ed3…

MALICIOUS

PDF

71.1 KB Created: 2021-09-08 05:07:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 473554d65cc7197fd8a4925becfa4b81 SHA-1: 97e96214f1847c655a4a95bcfaff31ff662cd660 SHA-256: 5b634cea1bea9ed3e9c372105dbe232fc4849e999727cb32d818040a977107db
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains numerous embedded URLs that point to compromised websites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious, and the heuristic firings suggest it is part of a link farm strategy. No scripts were extracted, but the primary attack pattern involves directing users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://coretry.ru/uplcv?utm_term=evinrude+etec+owners+manual PDF link annotation
    • http://bclgrouptt.com/userfiles/file/biminulabi.pdfIn PDF document text
    • http://fecoil.com/userfiles/file/dujaguzenepozege.pdfIn PDF document text
    • https://fatheragneliti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e138fb03c4a---xikubirinawimivujuw.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f22c1e509ad---12791385714.pdfIn PDF document text
    • http://atek-ent.com/upload/file/70736943076.pdfIn PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b2685a6d0f6---74806731695.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7a179cb85---80645006900.pdfIn PDF document text
    • http://momsystem.ru/public/file/20535912247.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/q8kncov6uunkh64b8snr28e8vk/86219868137.pdfIn PDF document text
    • http://lbs.ac.at/wp-content/plugins/super-forms/uploads/php/files/17leinrfgiqdi9359knnaqpe3o/punopojalalawigu.pdfIn PDF document text
    • http://babywagen24.de/userfiles/file/duwesog.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/nvjccghc6r6g4c878so2n2rlv4/tiloziwarekuzunig.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160beaef408de4---fubamakakebakira.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/0159465eef24d70aeb858b69f74da273/30824250596.pdfIn PDF document text
    • http://topstec.com/d/files/pomusuretumagopivevamoto.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/160becbc36cef1---felosuroxuzizul.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/22456283639.pdfIn PDF document text
    • https://bibliothequeanglaise.org/upload/files/bonudadegemevo.pdfIn PDF document text
    • http://xyr59.com/filespath/files/20210811220639.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/160c77bddf39e1---28871049528.pdfIn PDF document text
    • https://batikatravels.com/userfiles/file/9653284193.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16078ce8d21616---zovan.pdfIn PDF document text
    • http://valeneighbors.com/userimages/xokalosowerebarapubedaka.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/naludoruzosezopepug.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b671.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB671 10768 bytes
SHA-256: e35469acff26a0f09d850f227297c22ac98e14bd6578a1566035798e72df54d8
font_01_sfnt_off0000cf3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF3C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e74e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE74E 15836 bytes
SHA-256: f2666e5eeac61dba00522593f98f34a3258816990e05280b4a6c1dc920e870cc