Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bc18f4f489e5c67…

MALICIOUS

PDF

81.8 KB Created: 2021-08-21 10:59:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 79683c7659878cc0da071cbd928caccf SHA-1: 7169fcd0bcb56ccf66927435528d09b8ab647afb SHA-256: 1bc18f4f489e5c67786d02abecf283e80a78fedb76ddd84042122ab7458fbbb4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was identified as malicious by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to other PDFs hosted on compromised WordPress sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, suggesting an attempt to obscure the true malicious infrastructure. The primary attack pattern involves luring users to click on these links, likely leading to phishing or further malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1611ac27ac7686---bazipotetamo.pdf In PDF document text
    • https://apoiotelecom.com/imagens/img_fckeditor/file/61666247778.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/91474626150.pdfIn PDF document text
    • http://kmkonsult.cz/userfiles/file/67095186424.pdfIn PDF document text
    • https://www.milestonesmn.org/ckfinder/userfiles/files/kefekesivolokunefuge.pdfIn PDF document text
    • http://scro.ru/pic/file/wifekosel.pdfIn PDF document text
    • https://aedwea.com/upload/foto/8508367637.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/tixobotokeg.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/7289264972.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160823c83b8a95---varurizexug.pdfIn PDF document text
    • https://aaaxxion.info/images/file/46715529365.pdfIn PDF document text
    • http://thaihotelsale.com/FileData/ckfinder/files/20210710_1B8C510A475BD7BF.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1608faf2f8874b---81826400554.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/7910ce39c567edc5e3f5aacc4dadd287/midisusakuf.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/16084f903c6923---233987032.pdfIn PDF document text
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/885ivgrqth0bc5g6amc1bu8kht/niwazovafokitopaki.pdfIn PDF document text
    • http://aryajob.com/user_upload/file/gerirejiv.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/72re0139fba61h2ktb0s7dba25/lobibawibuve.pdfIn PDF document text
    • https://bloomeng.com/uploads/sewozupopukikowed.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/aa1f4488daad81f864285f4bf5d79b61/76024331832.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160920365459c2---36786034805.pdfIn PDF document text
    • https://faktxeber.com/resimler/files/rolivesunakeg.pdfIn PDF document text
    • https://www.andyselfstorage.co.uk/wp-content/plugins/super-forms/uploads/php/files/br2psh9agd9v8gurl65kbh5h1v/gedilemujowobejasokibuge.pdfIn PDF document text
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/16082c5f803862---mepewiradivasamiko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=rapport+de+stage+3eme+pharmacie+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_off0000d8a7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8A7 11136 bytes
SHA-256: e5651a5e712c2861d9209734b69328eb5c99e1c9a0a85eea741c45bf9b6aa331
font_01_sfnt_off0000f289.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF289 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010a9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A9B 18944 bytes
SHA-256: 012802193fba366c51b2a36f1b5a8dbd9cbc1f268ea3f18fec4b67240c344540