Malicious PDF — malware analysis report

Static analysis result for SHA-256 138adec8db2e02ae…

MALICIOUS

PDF

79.1 KB Created: 2021-09-21 08:20:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: bfa4b9fa41e87369ec3f8798b52bab87 SHA-1: 40ecbe6ff37c336e778c968f2d166b4cc5012c50 SHA-256: 138adec8db2e02ae38f799b2203580614110b08a6103ee60c6e8d657f11b664e
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload storage and disposable hosting, indicating a link farm designed to lure users to external sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://sibconsulting.com/contents/files/dumetijitunivefut.pdf In PDF document text
    • https://hr-serdahel.hu/images/file/simekulofovibiv.pdfIn PDF document text
    • http://roberthalasz.eu/uploads/file/85231502253.pdfIn PDF document text
    • https://safetyhanoi.com/userfiles/file/71713338155.pdfIn PDF document text
    • http://bebaldebaran.eu/userfiles/files/13376606752.pdfIn PDF document text
    • http://swhos.com/upload/files/rezozopeguza.pdfIn PDF document text
    • https://alrashed-alsaleh.com/userfiles/files/datakekejafaginepogi.pdfIn PDF document text
    • https://comptables-publics.fr/userfiles/file/zutomuwo.pdfIn PDF document text
    • http://mobitransjogja.com/files/betujagegetudobemewe.pdfIn PDF document text
    • http://vivaibonomo.it/userfiles/files/wovelerumarofala.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161328c3a14f6e---4671078810.pdfIn PDF document text
    • https://www.netcorp.hu/data/editorfile/57031592152.pdfIn PDF document text
    • https://grouptm2.com/contents/files/dipogijewekavefoduguzola.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/14803644455.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/dororipolibodidin.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/5mjusvkc0qs2jbs2m34c2vfut5/melatasotatasujonefubek.pdfIn PDF document text
    • http://rockycheng.com/ckfinder/userfiles/files/wagajavixi.pdfIn PDF document text
    • https://paymentor.nl/uploads/file/26659647296.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/xokejobubupimapibumen.pdfIn PDF document text
    • https://bostoncake888.com/UserFiles/files/gozomov.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/161314e60af493---35242730610.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/23139130052.pdfIn PDF document text
    • http://fabriziocar.it/userfiles/files/gemenubimukifuxotivo.pdfIn PDF document text
    • http://guanzhuli.com/userfiles/file/1003862390.pdfIn PDF document text
    • http://back2wood.de/userfiles/file/4270268096.pdfIn PDF document text
    • http://sinojjacob.com/userfiles/file/zexubuwikomofokodijezu.pdfIn PDF document text
    • http://jtylek.pl/Upload/file/fixedujatizefinanug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=glucose+molecular+formula+and+structurePDF 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_off0000d193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD193 17088 bytes
SHA-256: c00e0350ddd2ec0d9d505ac5a1f62779817fc9e60c3561c03b8a8493aab9d1e4
font_01_sfnt_off0000fdf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDF8 10684 bytes
SHA-256: 5e879beb210963bb34941f8b2a3ff52f7fa7abc5c40222aae3c232a20da54b74
font_02_sfnt_off00011688.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11688 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1