Malicious PDF — malware analysis report

Static analysis result for SHA-256 811c0bbe85afb7aa…

MALICIOUS

PDF

82.4 KB Created: 2021-09-02 13:01:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 05f2a669de4c3d74008c65da36c92ab2 SHA-1: 1bd6774cf52fa2e99b0db379b265b8b6c09a7d08 SHA-256: 811c0bbe85afb7aaef7c7cea2a5f2de3fd0f374a53c0b757e2b9a29d6632c930
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple websites, many of which are hosted on compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The document's structure and embedded URLs suggest it's designed to redirect users to potentially malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://thieumaunao.vn/workspace/develop/uploads/ck_upload/files/tugagusog.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612a3e7a7cc6c---13564080548.pdf
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/k7jkeosscks75h9uj5efpl9q8e/17070089166.pdf
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/7pdo43emgvgb9rmtbmsqr87iu9/dajilulujoxozubaripez.pdf
    • http://peterpan1996.it/userfiles/files/mojikusoweripuf.pdf
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/d8f045e4a7d19a0ef9ee5585faf1663c/12174916871.pdf
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/88023f9a6c26c0bc5e084d86be6a2606/xuxisunovumogilosenamiv.pdf
    • http://imtac.net/upload/files/29378875246.pdf
    • http://abaj.cz/UserFiles/File/15144291114.pdf
    • http://av-jet.ru/userfiles/file/tatav.pdf
    • http://elitacasa.it/images/file/71462689555.pdf
    • https://thaiwoodengames.com/files/upload/files/popalitulabofodifokelu.pdf
    • https://hv2barrier.com/application/third_party/ckfinder/userfiles/files/gazokomok.pdf
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/s9m82kmmoe3cjrtm1qaq7a66q1/jepisarezus.pdf
    • http://consulcongress.it/uploads/assets/file/zufamogisilakix.pdf
    • http://1hozain.ru/files/userfiles/files/rinixin.pdf
    • https://groupunsur3.com/contents//files/69977956961.pdf
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/530581a515459fe51e62b77c5a831456/vudobigoli.pdf
    • https://e-tta.com/app/webroot/userfiles/files/vefigese.pdf
    • http://irinaburmistrova.ru/files/fekokitofoka.pdf
    • http://re-view.online/fckFiles/file/35149098470.pdf
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/fqg3pl5roc862naqo2te23ef6f/padujigajosakup.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=como+unir+varios+pdf+en+uno+solo+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_off0000db22.bin
2ea97e9b92964fce8ade8312b5b1c9241dbcb67d507df4e8c59259a4e134d7dc
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB22 18756 bytes
font_01_sfnt_off00010b1d.bin
37c82b55d595ca76bb798a4eb4112e1e555ff6c899847b54fc678952912cc350
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B1D 10756 bytes
font_02_sfnt_off000123d7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x123D7 16792 bytes