Malicious PDF — malware analysis report

Static analysis result for SHA-256 25a50acf6e04769f…

MALICIOUS

PDF

81.2 KB Created: 2021-09-13 11:01:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: adba6c6b16703d19c374d34277ac0d22 SHA-1: 607d0f1d6e92adcb6d70a1450c732c697fe9dec9 SHA-256: 25a50acf6e04769f14d10229ecc10dc7c16835f5a4913e9c239afbdf8e36b698
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or link farms, suggesting an attempt to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the PDF is part of a link farm hosted on potentially compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://terrebleue.org/userfiles/file/vafaf.pdf In PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/b7fd30ecb13e5c88af6190442fbcdc10/57096845351.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc53c7a61b---vuxufunizinesakugimodimo.pdfIn PDF document text
    • http://www.insight-assessment.com/ckfinder/userfiles/files/94864505700.pdfIn PDF document text
    • https://strategieb2b.ca/userfiles/file/91076468417.pdfIn PDF document text
    • http://fygl.net/uploads/file/070007075787.pdfIn PDF document text
    • https://bahia-group.com/ckfinder/userfiles/files/pofegofabozi.pdfIn PDF document text
    • http://3bbb.fr/ckeditor/upload/files/sujipukikudun.pdfIn PDF document text
    • http://turhantur.com/turhantur/files/26758308577.pdfIn PDF document text
    • https://buddhaart.in/userfiles/file/pegitegiru.pdfIn PDF document text
    • http://aczelzalog.hu/tmp/99382097783.pdfIn PDF document text
    • https://saptabangunmanunggal.com/indomobils/upload/file/mudifezutiwusazefal.pdfIn PDF document text
    • http://turhantur.com/turhantur/files/17899837125.pdfIn PDF document text
    • http://ziva-muzika.cz/files/file/fojojodiduferijes.pdfIn PDF document text
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/46625033693.pdfIn PDF document text
    • http://xn--90aoaidn.xn--p1ai/ckfinder/userfiles/files/lekugobiwobemovopavewaros.pdfIn PDF document text
    • https://saraelv.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613594dcec618---mosigeroraxe.pdfIn PDF document text
    • http://nwatchonline.org/userfiles/file/mosasak.pdfIn PDF document text
    • http://lokalsport.no/userfiles/file/76661416292.pdfIn PDF document text
    • http://igabana.com/upfolder/e/files/20210909054438.pdfIn PDF document text
    • http://the100voicesofgospel.de/fichiers/newsletter/file/78590206415.pdfIn PDF document text
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/sekuliwega.pdfIn PDF document text
    • http://dansensvenner.dk/imagesfile///koxuzafufufolet.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+restore+my+phone+to+an+earlier+datePDF 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_off0000d783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD783 17688 bytes
SHA-256: d9c9107c6febf8c2ab02cfcf1b8cbde725c5437f475bdac1b2d4068c447fb468
font_01_sfnt_off0001061c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1061C 10848 bytes
SHA-256: 243ce0efdc6e6c5beab840c1d77924b23f6e0a9813556b1a156f7f913781e4c1
font_02_sfnt_off00011f04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1