Malicious PDF — malware analysis report

Static analysis result for SHA-256 e7ef81b2e260e57f…

MALICIOUS

PDF

98.8 KB Created: 2021-10-07 14:51:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 0c28bc6b0a2b49767c8440d4966c3e8d SHA-1: d151b26127c141fa5804c3d8aa8f06fbd53d8819 SHA-256: e7ef81b2e260e57f9c49c0527feadd8d1b8f664f82d7bb01cda383f838aa798c
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple URLs, many of which are hosted on compromised WordPress upload directories, suggesting an attempt to distribute further malicious content or phish users. No scripts were extracted, and the document body was unreadable, limiting the analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16138a6a563915---sebozapef.pdf In PDF document text
    • http://bekkercoon.ru/ckfinder/userfiles/files/pujikaputegetusidufuju.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1615e2adc54aba---36062279171.pdfIn PDF document text
    • http://gptools.net/userfiles/file/20915817244.pdfIn PDF document text
    • https://pbchistoryonline.org/uploads/file/54792555059.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/b4ae0022afe2d88e1b61b7189829502a/gewepurejomisaval.pdfIn PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/72810397239.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/82052312728.pdfIn PDF document text
    • http://klubbelgickychobrov.sk/editor_uploads/files/26896996868.pdfIn PDF document text
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202109021650099507.pdfIn PDF document text
    • http://robertwestlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/7825081238.pdfIn PDF document text
    • http://kutyasturak.hu/images/files/videbudemif.pdfIn PDF document text
    • http://synhbio.com/upload/files/22741706264.pdfIn PDF document text
    • https://epm.jot-solutions.com/files/fezete.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e64dfadde0---nusesazivefelagoxe.pdfIn PDF document text
    • http://warmistore.com/userfiles/file/nutelapikulag.pdfIn PDF document text
    • http://www.scea.edu.mn/ckfinder/userfiles/files/8310643227.pdfIn PDF document text
    • https://paramourpourbebe.com/userfiles/file/6910769269.pdfIn PDF document text
    • https://chambres-lannion.fr/userfiles/file/77378339347.pdfIn PDF document text
    • https://pielinks.com/UserFiles/file/pebifo.pdfIn PDF document text
    • http://akiisushi.com/uploads/files/fodugija.pdfIn PDF document text
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/4542f4b9243854a0dbddf8a72ad47f22/muwarajomilimimajafe.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/dibawi.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150cfc92e683---sajereroxetalupixopajupe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=reproductive+system+of+fishPDF 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_off00011648.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11648 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012e5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E5A 20720 bytes
SHA-256: 8e7710dd61e0abc8e601be1cc0586f374e7ec3aafb34eba978e9795685bb1c4b
font_02_sfnt_off0001645d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1645D 10900 bytes
SHA-256: 2d65320a538a3f989a47056df9b4808333ea571a0e8ce4b543bd86e73fd30c28