Malicious PDF — malware analysis report

Static analysis result for SHA-256 28f879f6dfea0833…

MALICIOUS

PDF

93.9 KB Created: 2021-09-20 02:28:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a282283ea02f09293ce83566767c9e5c SHA-1: ec102a15c6557bd4ebb9bb325cd1cfb6b5ea0389 SHA-256: 28f879f6dfea0833bb7cac81b34aa9da677aaecdc500b971d19bba4d3df95721
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and a link farm on disposable hosting supports this assessment.

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://nomylo.ru/uplcv?utm_term=how+to+write+introduction+for+argumentative+essay PDF link annotation
    • http://fitviewer.com/files/file/fatakuviloxifujaxo.pdfIn PDF document text
    • http://katela.net/userData/board/file/90433884637.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/53273742588.pdfIn PDF document text
    • https://jatransfer.com/userfiles/file/gejizedutadaji.pdfIn PDF document text
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/161401c055af44---xomowazusabo.pdfIn PDF document text
    • http://shannonlakeestates.org/fck_images/file/zirizojofexoxezeranat.pdfIn PDF document text
    • https://cam-ceeds.org/ckfinder/userfiles/files/84547955880.pdfIn PDF document text
    • http://matsusushionline.com/uploads/files/91071506818.pdfIn PDF document text
    • https://actor-conseil.com/files/file/65078150694.pdfIn PDF document text
    • https://servauto.fr/img/user/file/fokef.pdfIn PDF document text
    • https://pragatitic.org/ckfinder/userfiles/files/madovodasobuwupatodota.pdfIn PDF document text
    • http://upasamed.org/Content/uploads/files/jakilatasudirabovivifexo.pdfIn PDF document text
    • http://irollee.com/userfiles/file/xavuvujofep.pdfIn PDF document text
    • https://faresaldabbous.com/uploads/file/18997536200.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/j687totd4g15h8o11hqgav5bqo/58850878446.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/f99993124114b6bcab7b554231f46a9b/23075926582.pdfIn PDF document text
    • http://sz-nuoyi.com/Upload/file/2021090110074613802.pdfIn PDF document text
    • http://azbuka-d.ru/ckfinder/userfiles/files/54644218239.pdfIn PDF document text
    • https://dongcohonda.com/userfiles/file/mozenowet.pdfIn PDF document text
    • http://simsvizag.com/contentimages/file/21361716871.pdfIn PDF document text
    • http://effekt-film.de/files/file/xovafixanefotakoxawedesaw.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///72409328343.pdfIn PDF document text
    • 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_off00010a01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A01 11132 bytes
SHA-256: 1f17fdf0bc33430f32e271ba8d4c64b6a77502231ea7c96636832df30c985476
font_01_sfnt_off000123d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123D4 17716 bytes
SHA-256: f76bf66f309f25491468020d4706ab72ed079aaa458d919c8dc2d79535868c49
font_02_sfnt_off00015193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15193 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1