Malicious PDF — malware analysis report

Static analysis result for SHA-256 e40b8b9dcb7137a3…

MALICIOUS

PDF

74.0 KB Created: 2021-09-23 04:09:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0fdea9c3fc8991993aa76da9872c2fc4 SHA-1: fccd56a6795d0928a7d2f1bfd77e1661c18df76a SHA-256: e40b8b9dcb7137a3a063876911af22ac36cfa0e73b4875a6f408915839841612
196 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm containing numerous external URIs, many hosted on compromised or disposable domains, suggesting a phishing or malware distribution attempt. The presence of 'wkhtmltopdf' in metadata indicates it was likely generated by a tool, not a standard document editor.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://ketchas.ru/uplcv?utm_term=free+ios+theme+for+android
    • http://ziguratex.com/helpdesk/app/webroot/img/userfiles/files/pufubuguw.pdf
    • http://gzlmjx.com/data/home/bxu2343160066/htdocs/uploadfile/files/90936267066.pdf
    • https://mama-light.net/business_school/uploads/file/89521455849.pdf
    • https://nceptionsolutions.com/wp-content/plugins/super-forms/uploads/php/files/c597e2f0297ced08e46801614309e617/2058585245.pdf
    • https://intrastorg.com/userfiles/file/pirilawamunob.pdf
    • http://educaholistica.com/resources/img/imagesck/files/dixafowute.pdf
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144dd43099b8---29451629557.pdf
    • http://www.siscard.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141f3d66a4fc---54614826234.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614878958a034---widejagosodafofole.pdf
    • https://www.jdconstinc.com/ckfinder/userfiles/files/57624822362.pdf
    • http://dobermanncz.eu/files/budawofavegema.pdf
    • http://gianenricofabro.com/userfiles/files/91474966842.pdf
    • https://raselapp.com/userfiles/file/46989870271.pdf
    • http://onlinepravenconsultant.com/uploads/wysiwyg/files/30662585301.pdf
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/nivivuvazuzazuvunamudira.pdf
    • http://yameitecl.com/ckfinder/userfiles/files/20210917_105031.pdf
    • http://charmingcurls.se/upload/file/matumawaxo.pdf
    • https://oreopay58.com/ckfinder/userfiles/files/sedebadezisovezajavafixu.pdf
    • http://besttailor.info/ckfinder/userfiles/files/42680164987.pdf
    • http://bolt.fo/public_html/userfiles/files/puxewikipul.pdf
    • https://manhalhealing.com/userfiles/file/bewixupelezosipur.pdf
    • http://derp74.fooden.com/UserFiles/files/duturajub.pdf
    • http://istvietnam.com/rich_editor/file/domebagitexito.pdf
    • http://aftp.bg/userfiles/file/jijaf.pdf
    • http://comitatoamiantovelodromo.org/userfiles/file/96173177097.pdf
    • http://lemma-studio.pl/userfiles/file/jezajipaxidudom.pdf
    • https://oreopay58.com/ck
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c297.bin
de6b81f35b94a036321d0266db0d5700f871eb6eb78026a118816a8a05f07aad
pdf-font-stream PDF embedded font (sfnt) at offset 0xC297 15588 bytes
font_01_sfnt_off0000ea05.bin
09210766ea4c8aa3bed1d8febd5460b0f7355bcd864cd1c55fc1a633201bbbcd
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA05 10548 bytes
font_02_sfnt_off000101e3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x101E3 16792 bytes