Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4e28d9cc13100e1…

MALICIOUS

PDF

81.1 KB Created: 2021-09-17 11:23:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1ecba14aa4633bfb41d2cafb6023b416 SHA-1: 9c2727d5e464d9829cb5b189f29a0dc06d0a288e SHA-256: c4e28d9cc13100e135a51e59d39a64609aa32c3353e8a65bf2b0da314820ea57
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous external URIs and link farms, with several pointing to compromised WordPress upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery through these links. The document body is heavily obfuscated and unreadable, providing no direct content clues.

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://crewmak.ru/uplcv?utm_term=paranoid+lyrics+russ PDF link annotation
    • http://pro-customer.de/userfiles/file/52807277166.pdfIn PDF document text
    • http://xn----dtbhwhggdaoqfh3d.xn--p1ai/media/file/zuduvibowemapaka.pdfIn PDF document text
    • http://club-integra.ru/userfiles/file/dalizimeseramuwemojuke.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/nagisekojovopidoruwa.pdfIn PDF document text
    • http://business-plan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/62191923724.pdfIn PDF document text
    • http://tubesealer.com/uploaded/file/32370417661397ad7cf264.pdfIn PDF document text
    • https://sakkestadbil.no/userfiles/file/58346529655.pdfIn PDF document text
    • https://mmeasar.com/mmeasarfiles/file/lavodowep.pdfIn PDF document text
    • https://educhina.mn/editor/files/dejewutef.pdfIn PDF document text
    • http://mansiya.com/uploadfile/files/94229046529.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137ab7633050---melumugila.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021090905365773499.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/zuwalugigirano.pdfIn PDF document text
    • http://sdhmladavozice.cz/userfiles/file/zutatesasatavireto.pdfIn PDF document text
    • https://gs-hemeringen.de/ablage/userfiles/files/fadujewenunijelazi.pdfIn PDF document text
    • https://menu2uplus.com/images/file/xezobadodiroje.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb7e8de89d---zaxodovupuzimunizepuv.pdfIn PDF document text
    • http://aligokdemir.com/resimler/files/dezugitex.pdfIn PDF document text
    • https://kalatranslation.co.uk/wp-content/plugins/super-forms/uploads/php/files/f49qlrlqag27lu9e3u4dc969po/kabevejabogoju.pdfIn PDF document text
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/rofonomoserofex.pdfIn PDF document text
    • http://www.heksan.com.pl/file/safaxepadonazesedita.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/16692310678.pdfIn PDF document text
    • http://bagiez.de/userfiles/file/45048059882.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/roleviwagenolava.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2dd367745---xanino.pdfIn PDF document text
    • http://duocmyphamcongty.com/app/webroot/uploads/files/93665135484.pdfIn PDF document text
    • http://huijingweb.com/upload_fck/file/2021-9-10/20210910091946262808.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_off0000d900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD900 17984 bytes
SHA-256: c449785f76062ff22385e9ec5332981cf05bb45bcbe13ba68fe736ba08df84ba
font_01_sfnt_off000107a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A2 10348 bytes
SHA-256: 40124faad719001740dfae3664bb5535d73f7d38e22f1e2a186f8e4c7c580dee
font_02_sfnt_off00011f12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F12 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1