Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cb727217a53a2c4…

MALICIOUS

PDF

87.9 KB Created: 2021-08-17 09:28:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: c7bdb76971ba111c9e68b5cf4d3c52d6 SHA-1: 26f3d08154e1cd135e69a5e911e74b4655c0a264 SHA-256: 1cb727217a53a2c48f2765c8fd0f90b69b50f6f8d19542b26f8a1b4e5fd11e97
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified the document as a link farm, with numerous external URIs pointing to potentially compromised WordPress upload directories and disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9914

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://przedszkolenisko.pl/userfiles/file/sefobokeruzonekesepepote.pdf In PDF document text
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/92469be6930559312b790bec8ede24a5/3595152969.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/899ed4fb659d4e602688865fe2ee03e2/83359120134.pdfIn PDF document text
    • http://clinicacomciencia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c2f035d7c76---73472790888.pdfIn PDF document text
    • http://sergey-yushkov.com/pict/file/jepabilizevudubilaval.pdfIn PDF document text
    • https://tyeetomsfishing.com/userfiles/file/9881948956.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/vaxofibalutij.pdfIn PDF document text
    • https://binarbaidtrading.com/public_html/userfiles/file/subikis.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a0171239cd2---zediximivakituxabogazi.pdfIn PDF document text
    • http://jointrilogy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a824c0c99---juvuka.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16093c3d23e3c0---22285291149.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/66c17c4bdbd685cb6aa2219f9fc51696/xuvoraliwufogajate.pdfIn PDF document text
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608f229c4834b---10570555841.pdfIn PDF document text
    • https://speculatio.in/userfiles/file/watomimabobim.pdfIn PDF document text
    • https://himarco.ir/basefile/himarcoir/files/75655904079.pdfIn PDF document text
    • https://www.harnoordesigns.com/wp-content/plugins/super-forms/uploads/php/files/89gt6g0vp2s3vnufp73c79jfc5/wekikodilinixelew.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/160866de034591---wutomegigasisijiboxura.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/gunixidufuvinovilifikax.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/21262590124.pdfIn PDF document text
    • http://klick-tipp.info/ckfinder/userfiles/publics/files/75636305011.pdfIn PDF document text
    • http://irmascaritasdejesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b64d790570b---sopifo.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/v0oe798fib7infe75ig011b36t/9170371458.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/gasixizid.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/6283059474.pdfIn PDF document text
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee54b3841c5---wopubafexi.pdfIn PDF document text
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/5392b6c9400a7b03731cd5a2fba5adc9/wiganuw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=manual+de+instrucciones+microondas+orbegozo+mig+1810PDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e344.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE344 11388 bytes
SHA-256: e25b00364bcafa95cf5e2bf56d721fe2749405f9044deb464813b07484338ebe
font_01_sfnt_off0000fdee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEE 18492 bytes
SHA-256: 76a17ab3cdbdbdeed92e71d9e448e2b5116f79d7bdd4241023fad077eae739f8
font_02_sfnt_off00012db6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB6 1732 bytes
SHA-256: 5b3c947262022625ef2d4cfb2d0fa10a94f23c97611fd4c7364bfcc62a76ce6a
font_03_sfnt_off000135ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x135EA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1