Malicious PDF — malware analysis report

Static analysis result for SHA-256 6badf79b4d572368…

MALICIOUS

PDF

79.7 KB Created: 2021-09-09 03:56:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a807435a491acd0260b8c06ba9c7527b SHA-1: f469e8b39c7619f96ae2115b8c64f4e0fcaaeb1a SHA-256: 6badf79b4d5723688910039224f6c980519406c6576ad397c034c6ce09b6177d
156 Risk Score

Malware Insights

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

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to compromised WordPress upload storage and other disposable hosting, suggesting a link farm designed to redirect users. The PDF structure itself appears to be generated by wkhtmltopdf, a tool often used to create documents from web content, further supporting the idea that it's a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161317a0cb7dfa---varawevarazi.pdf In PDF document text
    • https://probidjp.com/ckfinder/userfiles/files/20210908_205713.pdfIn PDF document text
    • http://cctechlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/38956753341.pdfIn PDF document text
    • http://liily.jp/upload/file/20210909091123.pdfIn PDF document text
    • http://juentai.com/userfiles/files/rokoridonedagisopidosa.pdfIn PDF document text
    • https://myclubowners.travelenvogue.com/userfiles/files/xizuvafexaxowun.pdfIn PDF document text
    • https://galaxytraining.examinationonline.com/files/bedovumaviwalidiped.pdfIn PDF document text
    • http://www.slenderclub.cz/ckfinder/userfiles/files/89039222797.pdfIn PDF document text
    • http://www.koeru.eu/failid/file/31352395291.pdfIn PDF document text
    • https://unicon-msk.ru/data/files/28401805426.pdfIn PDF document text
    • http://poliinc.com/upload/files/18572525608.pdfIn PDF document text
    • http://print-resource.co.uk/ckfinder/userfiles/files/rotesexulo.pdfIn PDF document text
    • http://sangjeom.com/userfiles/file///jatij.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/161319540864c1---tawatuxaloxexezivube.pdfIn PDF document text
    • http://studioriboldi.eu/userfiles/files/83851952539.pdfIn PDF document text
    • http://zhymwz.com/upfile/file/jadajufuzakinokogotenige.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/275f3878f1d091ee37b7ebe9ef9463fe/57650368779.pdfIn PDF document text
    • http://www.ujepites.hu/userfiles/files/41850737044.pdfIn PDF document text
    • http://autoservizimensi.it/images/fck/file/41565334075.pdfIn PDF document text
    • http://melissajacksonmd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134ca3d3f685---26145465659.pdfIn PDF document text
    • http://hindustanadvancedsolution.com/t/tutorfirm/uploads/ck/files/nidexire.pdfIn PDF document text
    • https://bdprescription.com/ci/userfiles/files/5361156783.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=android+record+screen+videoPDF 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_off0000d423.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD423 18008 bytes
SHA-256: 67d93d78426f0beef17d5f832b57d41485c382d54d57a0047381f50506ccccad
font_01_sfnt_off0001026f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1026F 10104 bytes
SHA-256: c347b427d86e05b8843d37e5417b1e80165060290ab0873bd0fe2012f93e9885
font_02_sfnt_off00011917.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11917 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1