Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b4c3cf870bb861a…

MALICIOUS

PDF

86.8 KB Created: 2021-09-18 04:51:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 57e68250d1cf8a30a6fa6647b7fb68d2 SHA-1: bb0e4314eb320f0ab53b87a9cf833992cee6cf55 SHA-256: 3b4c3cf870bb861a169eb55c2cd766512b8f5efec3ded144761f754610499144
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malware or phish users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9905

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://nusantarabet4d1.com/contents/files/fizetuwakuz.pdf In PDF document text
    • http://preprod.app-nomads.com/ugecam/admin/ckfinder/userfiles/files/jiwojizutepaxugu.pdfIn PDF document text
    • http://klusjesindex.nl/images/uploads/notuwalasimobosikaxolun.pdfIn PDF document text
    • https://breedlife.com/upload/files/71703586031.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/95820984091.pdfIn PDF document text
    • http://campbellelectronics.com/uploads/57374596417.pdfIn PDF document text
    • http://sintniklaas.kinderopvangpimpeloentje.be/ckfinder/userfiles/files/8384397893.pdfIn PDF document text
    • https://jamurgoreng.net/contents/files/zudaloxarugej.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613664891b77f---77359120126.pdfIn PDF document text
    • http://cgmorenanews.com.br/ckfinder/userfiles/files/lonawusinenoruvamixeb.pdfIn PDF document text
    • http://www.ez4parcel.net/upfile/files/2021/09/17/3155116399.pdfIn PDF document text
    • https://domilot.com/uploader/files/mozimaxuwaz.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/0a2ba40b761acc05f4292b01f34e1afb/81227187824.pdfIn PDF document text
    • http://yotlist.com/uniformkontakt/userfiles/image/files/82345852453.pdfIn PDF document text
    • http://theartofdesign.nl/ckfinder/userfiles/files/72444470858.pdfIn PDF document text
    • http://zjnep.com/ckeditor/ckfinder/userfiles/files/9211480269.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/49536884990.pdfIn PDF document text
    • https://adamant54.ru/userfiles/files/lanimikuxa.pdfIn PDF document text
    • http://fecirturizm.com/resimler/files/fijaserugipawufasubofe.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/tokilogamagamojeki.pdfIn PDF document text
    • https://www.abrasco.org.br/ckfinder/userfiles/files/34782520622.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/9056785322.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613be8b5e277d---mofaxesurazilagat.pdfIn PDF document text
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/pijatebepazo.pdfIn PDF document text
    • https://fullgame.hu/uploads/files/vezerome.pdfIn PDF document text
    • http://safetyassessmentsolutions.co.uk/ckfinder/userfiles/files/92135878543.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/mulamukabi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=where+is+the+speaker+on+my+android+phonePDF 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_off0000ede6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDE6 10808 bytes
SHA-256: 4f5cadaeb099f30e31a70a4269edc1af5cf972806d67818e708825be3b18d8f3
font_01_sfnt_off000106b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106B3 17620 bytes
SHA-256: 1aba7b6d0a46c819ed7541bb3a97789e50e9e41637464441158cf9c3f3dcdea1
font_02_sfnt_off000134cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1