Malicious PDF — malware analysis report

Static analysis result for SHA-256 771acc18d5c4db16…

MALICIOUS

PDF

100.1 KB Created: 2021-06-26 05:48:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: df1053aec13849e9f99817f2959afe83 SHA-1: 9a8bc2a8d0af451eaa1f586d9dec92358b58c9e8 SHA-256: 771acc18d5c4db16250be033f610c77d55360c7bd5e8a51e5ee17615c8863b30
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the heuristic firings and URL analysis confirm a link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://technok.cz/wp-content/plugins/super-forms/uploads/php/files/8d45a270bc4492ce42924dc79639561e/siwebudufajazewozowepa.pdf
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8bbf439961---88351055629.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/egtq3got6hapnoo417i92b2jlh/jasonuririwapajidenumuk.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad1c4474b69---xumarojedimov.pdf
    • http://bahsclassof1965.com/clients/1/1d/1db829f64c2e26d3b32b12ccabba4d7c/File/4575141191.pdf
    • http://randalljroutson.com/clients/44711/File/gopusuruwotovafi.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609469ef8b020---64642034973.pdf
    • http://kameleonhastanc.hu/files/file/45052700304.pdf
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/1607c4064e0e44---zasakudatilazapizijosi.pdf
    • http://drivingschool-brno.eu/files/rubixa.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/5fssaivj88rk6rhfe6glo9aj15/jezozogejiruluverinagafi.pdf
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c88b3d3728d---ririrezomoviduta.pdf
    • http://vejwun.cz/images/tatusewijiburovunanave.pdf
    • http://bright-mineral.com/uploadfile/file/2021061023033525.pdf
    • http://aceonlinementors.com/userfiles/file/47717032442.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bfe1330b940---87192862933.pdf
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/b1aac446829d4fcd7f76770d0d983267/22929509113.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076c76639e7d---39460564538.pdf
    • http://baigeleather.com/userfiles/file/gugaziwu.pdf
    • https://funkydrop.shop/wp-content/plugins/super-forms/uploads/php/files/18f8371f37c7593b7b3162035ea87c26/15975827088.pdf
    • https://actorconseil.com/files/file/87834127938.pdf
    • http://donauwell.at/userfiles/file/gonafa.pdf
    • http://shinies.ru/img/lib/file/79434381893.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16086a3f1c4051---67577100828.pdf
    • http://tikatalog.sk/_files/file/tufizutuvuxebomux.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=nih+stroke+scale+answers+test+a
    • 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_off00012451.bin
6077acfe9af613c1554a1a675124f7289a64faf157c0d833f9df404edd36c29b
pdf-font-stream PDF embedded font (sfnt) at offset 0x12451 17812 bytes
font_01_sfnt_off000152bb.bin
c656b17208468988b870e8d031932b2c5c2c1f64f5d1cf7d8939f9f75124c6c0
pdf-font-stream PDF embedded font (sfnt) at offset 0x152BB 10484 bytes
font_02_sfnt_off00016a99.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16A99 16792 bytes