Malicious PDF — malware analysis report

Static analysis result for SHA-256 687f8d210ed48889…

MALICIOUS

PDF

134.7 KB Created: 2021-07-03 08:05:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 54a54ae0704d4f005ddebf610c815aa9 SHA-1: 7e69d32eb17a825b98a200649a5b034c36d38801 SHA-256: 687f8d210ed48889fee7cd945913a4fc9d0be589515d443d1299797c6af927e9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by ClamAV and an ML classifier. It contains numerous external URIs pointing to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users. The PDF structure itself is heavily obfuscated, and while no explicit scripts were extracted, the presence of numerous external links indicates an attempt to lead the user to malicious content, likely for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://wastran.ru/uplcv?utm_term=field+hockey+positions+and+rules PDF link annotation
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607684a6d41d4---16528854083.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160c63b4ce4703---fasolusu.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/roxabapokifo.pdfIn PDF document text
    • https://rebel-guitars.com/wp-content/plugins/super-forms/uploads/php/files/fcc069795b84a1a155d0ce9b86cb0640/begijalasatonodejizako.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/ce46bbe8e022bfe6b78fe9be04d2c92a/36830599180.pdfIn PDF document text
    • http://edgecs.net/documents/purem.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/9e135e20591ed317bf4cff996721d66f/gironuxozowemudax.pdfIn PDF document text
    • http://emeat.ru/var/files/maxilonosikifanef.pdfIn PDF document text
    • http://ekolojikweb.net/upld/userfiles/file/85000735699.pdfIn PDF document text
    • http://1960whs.com/clients/7/73/73384dfd0d582a2861cf356c55c3c578/File/kudobim.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/sivekonavidikeridefubi.pdfIn PDF document text
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/9s1ode60ogcgt00par0br5ip25/3917118467.pdfIn PDF document text
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/wikotuvi.pdfIn PDF document text
    • http://bradleyhillsapartments.com/demo/uploads/contents/file/82748051974.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/73aff373cca1219e647c24d0d1e1d2e7/94729246764.pdfIn PDF document text
    • https://makemycake.gr/wp-content/plugins/super-forms/uploads/php/files/6po0mj2doumjrnchfuv6nnf4h3/92182757692.pdfIn PDF document text
    • https://kermiradiatoriai.lt/images/files/80898510499.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160de66ec647e3---50127995428.pdfIn PDF document text
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/r66hb5bnahehhtjjsdt7bp0bif/70814483012.pdfIn PDF document text
    • http://ineke-ott.nl/keramiek-beelden-imagesfile/19534793314.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/8535224911.pdfIn PDF document text
    • https://kindliving.org/wp-content/plugins/super-forms/uploads/php/files/tmp/96482598236.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/7cb0885858a282ba67c5ccefb49f3617/11027045956.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/12130335501.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c88d643c3b---66557945846.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_off0001a758.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A758 20164 bytes
SHA-256: 94158730a40dfda828eebb773160fe5f403f5d7080012e2b6f020f6a4fa86888
font_01_sfnt_off0001dbca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1DBCA 10892 bytes
SHA-256: 30d8f4d85fefb4a8553c588b3bb8542f5e68c2baf915280524f9748a2e821e5b
font_02_sfnt_off0001f4f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1F4F5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1