Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a78e6a2588455e8…

MALICIOUS

PDF

85.2 KB Created: 2021-07-06 13:45:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7b39dfc1571442f0fe0a6b18730ea492 SHA-1: c48f13623ca966a51b17cec790d1b38b57ab2137 SHA-256: 5a78e6a2588455e8a7e5e5041c632ba9eb2bd5a9cd2457898d7c91062b6d178d
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URLs are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://nomylo.ru/uplcv?utm_term=what+is+trailing+stop+limit
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16087d734c4f03---zovomipitotatotepedo.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085e01461b67---jigofesigosir.pdf
    • http://dui-antidote.com/images/userfiles/file/93819316636.pdf
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/gcv8bpiq0igk8ca53a27t73g73/8007652953.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/3c3eb2f8e48a5a283596b60d525e7999/73147969059.pdf
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160d504ed467b1---winebojupomilovipisuz.pdf
    • http://marthomaiticherukole.com/userfiles/file/38077462095.pdf
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081919e5e1dc---wedikedigujulikoxuwo.pdf
    • https://sanxuattrucauthangkinh.com/Images_upload/files/55245192020.pdf
    • https://bechtoldpaving.com/wp-content/plugins/super-forms/uploads/php/files/2030c631465f79db52512c2472d3a32c/27103974670.pdf
    • http://files.ibiza-ferien.de/file/ditulove.pdf
    • https://tractorpulling-emmeloord.nl/upload/file/87354391081.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b296cc68b83---voforepituzokaju.pdf
    • http://quaint-house.com/69823007472.pdf
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1607120e919a88---jatagukegafivor.pdf
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160aae12a513b8---betuwa.pdf
    • http://vita24h.com/uploads/userfiles/file/bedot.pdf
    • http://norilskgu.ru/userfiles/file/jarexopulev.pdf
    • http://alibabashipping.com/userfiles/file/25912497934.pdf
    • http://giga.sk/storage/file/75723033625.pdf
    • http://mirembeestate.co.ug/wp-content/plugins/formcraft/file-upload/server/content/files/160c5d3c302b6f---vomaf.pdf
    • http://accessiblevehicleservices.com/userfiles/file/radetovuxubugar.pdf
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/61451798e0497fa07b4ed13a1c4d90e9/xewiza.pdf
    • https://publicbridge.pl/userfiles/file/71375610556.pdf
    • http://paskolik.com/upload_files/fck/file///18151475941.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea7b.bin
3e41420a2d36df46063f460e226c8cb2340bf9a1fc6dd75cb1779fdc42e8bfc7
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA7B 10560 bytes
font_01_sfnt_off00010259.bin
82b157f9e934ce1f4c098c25a0377880050f06d6316a7e3ea3637eb8634a14f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x10259 16844 bytes
font_02_sfnt_off00012dfc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DFC 16792 bytes