Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f2ef2a37e99effd…

MALICIOUS

PDF

80.1 KB Created: 2021-09-04 14:52:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8bcc8ff2d0ba035b1b07b52c411843a0 SHA-1: 8b546be8519a9af79ac1609b2a9db2ceceec0781 SHA-256: 5f2ef2a37e99effdf361710466d6b9ae928d03eb22c67d979cd56e9626a232de
96 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many of which point to compromised CMS uploads or disposable hosting. The ML classifier strongly indicates maliciousness. The primary purpose appears to be a link farm, likely for SEO manipulation or to distribute further malicious content, rather than a direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://bokaichenyu.com/upload/files/fepediwinedolopedagoj.pdf In PDF document text
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6eeda22bb5558e136cd935bec22e18fe/51498402185.pdfIn PDF document text
    • https://alshaabcoop.com/userfiles/file/20124709086.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/772fb733dfb7f6bb30f4573e6cdf478c/dexetasewowazipigovi.pdfIn PDF document text
    • https://www.makathastaliklari.net/wp-content/plugins/formcraft/file-upload/server/content/files/160789e94428cd---93091671372.pdfIn PDF document text
    • http://ip-golubev.ru/ckfinder/userfiles/files/14554867160.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2ccb870d1e---43602900846.pdfIn PDF document text
    • http://kochamsushi.pl/UserFiles/file/kekeboveguzejiramu.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/pintuiii9tdjecfo3a9a4nf6t3/xuvebosomorapi.pdfIn PDF document text
    • http://zap-interactive.com/uploads/files/dajowoja.pdfIn PDF document text
    • https://audit-advisers.com/userfiles/file/89577573758.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160708e758a0b6---natunidufelufopo.pdfIn PDF document text
    • https://manenshop.com/upload/files/widemoxe.pdfIn PDF document text
    • https://sgotomotiv.org/upload/files/tivujute.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/ffb36d65da32cf5d7c53030dc219791c/sewametejo.pdfIn PDF document text
    • http://artkulinaria.pl/sites/default/files/file/jigovifi.pdfIn PDF document text
    • http://nano-vip.com/ckfinder/userfiles/files/44642675549.pdfIn PDF document text
    • http://dmychadla.eu/UserFiles/File/redinivezedekajeva.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/64344eb1e1728c2df48e1376207ff25d/48265611331.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca708bb8b9---logazewaropafu.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/ur0qhdc7cfru69rtugtt6v3slu/pafidajimetadadevawapuf.pdfIn PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e3833c3057---56482233171.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=symbian+os+c%2B%2B+for+mobile+phones+pdfPDF 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_off0000d506.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD506 11116 bytes
SHA-256: dfc6705ec838de84aefd7ab52b252b382c99f167b88994bbefa646684414a11a
font_01_sfnt_off0000ee7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE7D 17280 bytes
SHA-256: 1c1c7f528ff090c6757a1a0ff832de11ba6417d50afafc9f145f4cc81dd2e247
font_02_sfnt_off00011b42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B42 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1