Malicious PDF — malware analysis report

Static analysis result for SHA-256 8efc0166fe1c4b45…

MALICIOUS

PDF

72.5 KB Created: 2021-09-06 10:10:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9fef744ff909b627ac5e3778626a7888 SHA-1: cdf28c8a72396a4e64b9b19b9cc135aec8e66713 SHA-256: 8efc0166fe1c4b45ae287ae4123949e4752655ad74a7912c0d5c8e48934092cb
156 Risk Score

Malware Insights

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

The PDF contains a large number of external URIs, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The document body is heavily obfuscated and does not provide clear textual clues, but the overall structure and heuristic firings suggest a link farm designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/2a032bb566f9222647bc302810acb552/muzagakasaseretamitojok.pdf In PDF document text
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/dpm0mqadtsi4ervff5ssar24ih/44891534674.pdfIn PDF document text
    • http://packamate.com/userfiles/16598241047.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/jrfibcbf9njc87kheap4d1lodi/fexapuganuzalitofogesetu.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/67111181895.pdfIn PDF document text
    • http://vhz.cz/user-files/61645264112.pdfIn PDF document text
    • https://gulfb2b.com/userfiles/file/60181254689.pdfIn PDF document text
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611a028dbe427---17729229582.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/leranowemavorekisexuf.pdfIn PDF document text
    • http://glovimex.com/uploads/ckfinder/files/dutev.pdfIn PDF document text
    • https://alharithiforcameras.com/ckfinder/userfiles/files/43584968314.pdfIn PDF document text
    • http://carnavaldemarbella.com/Senegal_5/Content/files/userfiles/file/57746183603.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/587c4a9c515e236461664b0c8d49d946/pujojixu.pdfIn PDF document text
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a5df7717e5---rezupotazoxesike.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/d755636b383c6ae31319ca0059a4efcd/24479065779.pdfIn PDF document text
    • http://oilspecchem.com/files/fipuvibanevimegosi.pdfIn PDF document text
    • http://ahdongjiu.com/upload_fck/file/2021-5-16/20210516150031749564.pdfIn PDF document text
    • http://healthywithhart.com/res/file/60945368492.pdfIn PDF document text
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1607095bb3e02f---29979629562.pdfIn PDF document text
    • http://avvocatoandreabruschi.it/userfiles/files/26375607024.pdfIn PDF document text
    • http://www.vikingmaterials.com/img/fupuvagat.pdfIn PDF document text
    • http://gonuldoviz.com/upload/ckfinder/files/22199298823.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160702e643fae6---46056870904.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=agricultural+biochemistry+book+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_off0000ba0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA0B 15420 bytes
SHA-256: 9dc5ebe3f6c526104fa1d11f1ef1fae43a4d4c27af0887632ee29d73c1668586
font_01_sfnt_off0000e196.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE196 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f9ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9AD 11392 bytes
SHA-256: 86c3b76820bc3cb89a61c110372168452e74b70a4d620c3af809967731e5caf8