Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a3255f75b7e6c2a…

MALICIOUS

PDF

93.8 KB Created: 2021-09-04 22:27:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 11aa6fc8d2751a79a1a95c078d7c8a15 SHA-1: 7acc5f8b07008c0dc37c487c1adf6dfe069358bb SHA-256: 7a3255f75b7e6c2a17bcb6a6aab0fb4fc72ca8cac363d76eff4b425e2bbd160e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by a machine learning classifier and ClamAV. It contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users to potentially malicious content. While no scripts were explicitly extracted, the nature of the link farm suggests an intent to facilitate phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://azco.friend-match.com/upload/files/92998204914.pdf In PDF document text
    • http://hvezda-pardubice.cz/files/file/18480715644.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/pevaziwopivefirekavinix.pdfIn PDF document text
    • http://csc-020.com/userfiles/file/20210626112824_v3lyy0.pdfIn PDF document text
    • https://jclifeschools.org/wp-content/plugins/super-forms/uploads/php/files/e93c8bc8a02bdac1b7cabc262ca2da3c/16269920561.pdfIn PDF document text
    • https://cs168.tw/upfiles/editor/files/lanitasowufok.pdfIn PDF document text
    • http://blackshirts1962.com/clients/f/f2/f245580d3072b78cda2271cf7a7e3f61/File/61890211090.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb2c7a12a9d---77148775402.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/3c3cffe25c8a0663a7d9e0b33d0adb2f/47593830681.pdfIn PDF document text
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/5smbp1sh7fcege55po80bpk1re/jeluxomemenidijovogu.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6f695474b8---93929454656.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/161338d2a4a0d5---vibojubarodutebinijuri.pdfIn PDF document text
    • https://sogelec-eng.com/files/ckfinder/files/30461871323.pdfIn PDF document text
    • https://www.die-umzugsfabrik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c845884e8b---doxexoderezapelinazuz.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160838e97db734---93849388030.pdfIn PDF document text
    • http://opuspointpartner.com/ckfinder/userfiles/files/tovuxibujujorokegelixosug.pdfIn PDF document text
    • https://hoongnau.com/upload/files/zoroku.pdfIn PDF document text
    • http://amandamaitland.com/images/file/tegitulokiwusewofuvod.pdfIn PDF document text
    • https://satybharat.com/ci/userfiles/files/39702814290.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/928bd3d8eea374c2f94f7a8ed670a514/90219613363.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cace4367b74---35982425672.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081ca1d4eb38---duvavisafazofajasasi.pdfIn PDF document text
    • http://karpatskiles.ru/store/file/47197277404.pdfIn PDF document text
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/zujuzo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=edgar+allan+poe+el+gato+negro+y+otros+cuentos+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_off00010712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10712 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011f24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F24 19420 bytes
SHA-256: 719693c33f735c427fd5898e1b88e9b743da74d0984b187a2cf0f3f48c2f8f96
font_02_sfnt_off00014fdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14FDF 10900 bytes
SHA-256: 85c45d84df29cdb5e95d7c71ff3d80204f109402b123dfa9655936e8b8cac42e