Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b853071b1a4ed6…

MALICIOUS

PDF

76.8 KB Created: 2021-08-02 02:06:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: a39741162b213020b6d2fc80b71af2b8 SHA-1: c15e5285adf05f7d7f3fba7932e26d4562a2ef5e SHA-256: a4b853071b1a4ed67ed99c236ddf2a4f37315b1ee16a494dbeb318333932cc83
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to external resources, many hosted on compromised or disposable domains. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, suggesting the PDF is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://irlanc.ru/uplcv?utm_term=diary+of+a+wimpy+kid+wrecking+ball+reading+level PDF link annotation
    • http://furniture83.com/upload/files/xefesekedujal.pdfIn PDF document text
    • http://mjsolankifoundation.com/fck/imagesfile/kamen.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/fosemanoroxofujudewuwavex.pdfIn PDF document text
    • http://www.eurosecurimed.com/ckfinder/userfiles/files/guzekajomajum.pdfIn PDF document text
    • http://yoga-privates.com/yoga-privates/file/pagutufizuvuri.pdfIn PDF document text
    • https://www.webplease.it/wp-content/plugins/super-forms/uploads/php/files/1hbdvaq723cjl6v282pln09ght/molosupimokorusejuvasas.pdfIn PDF document text
    • http://kondicionery-fryazino.ru/upload_picture/file/87642964010.pdfIn PDF document text
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/h934rkr6d7i1vibf5q01phr9l2/5496741839.pdfIn PDF document text
    • http://ilturismoinitalia.it/userfiles/files/niruvenonewupunowu.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2d25530f5a---28447277993.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa8265ebff---8113302812.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/709267a77fe3ea64cfd1971eebfbffcb/92949639688.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160819b1a04f10---10228612157.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/fusimakinudajiwumifow.pdfIn PDF document text
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfb6642873---tuludiwuges.pdfIn PDF document text
    • https://samarpanbharat.org/trila/userfiles/file/73943990887.pdfIn PDF document text
    • https://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/b2300b4fcc123b30f85f82590a9297e8/fokobebipaxobejovisizikar.pdfIn PDF document text
    • http://cdseoulps.com/uploadfile/fckeditor/file/jidixuxid.pdfIn PDF document text
    • https://actor-conseil.com/files/file/zusuxo.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160dbfac8a6c27---tediwum.pdfIn PDF document text
    • http://cameronhaddock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080b5043c148---37565322794.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1609996638409a---wibafawajabud.pdfIn PDF document text
    • http://kirilmazbardak.com/userfiles/file/memuk.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160831df512e32---22074506365.pdfIn PDF document text
    • 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_off0000c574.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC574 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD86 16940 bytes
SHA-256: 08fecc3c0d7b02538722edfa65abd51caa38da276a5057de66d6143981224584
font_02_sfnt_off00010a0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A0C 11196 bytes
SHA-256: ca6c66bbf5d7953ca6179ff62bf5a041a5e3916a87323741ed64b2151c819e85

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