Malicious PDF — malware analysis report

Static analysis result for SHA-256 70153584c9cdb8c2…

MALICIOUS

PDF

71.2 KB Created: 2021-09-28 11:05:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6cf232605ff9cd0e03f182d90eb0a889 SHA-1: 18c3f9324f0e294a162d33993a80d0354c4e03bf SHA-256: 70153584c9cdb8c2bfc6fdac31ac705d09e0738e3b8f5e54e6509a17201eb228
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous external links, many pointing to potentially compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics indicate a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://medvor.ru/uplcv?utm_term=english+idioms+in+use+advanced+book+with+answers+pdf
    • http://frutapacargentina.com/ckfinder/userfiles/files/29117594469.pdf
    • https://funbugs.ie/files/file/49731621903.pdf
    • https://k85shj16h-561lt.com/contents/files/7679094433.pdf
    • http://generaltubi.com/container/ckfiles/files/84460912562.pdf
    • https://pensiuneavalentina.ro/app/webroot/file/keduvada.pdf
    • http://cosyromania.com/media/file/83307717899.pdf
    • http://heimundsicherheit.de/userfiles/file/53182534373.pdf
    • http://irina-beha.com/ckfinder/userfiles/files/xafin.pdf
    • https://mkserwis.pl/userfiles/file/sogikubujagerefo.pdf
    • http://cartonwrappingmachine.com/userfiles/file/56366445562.pdf
    • http://nanouklid.cz/upload/file/1914486236.pdf
    • http://squarcialupirelaxinchianti.com/writable/public/userfiles/file/84905843606.pdf
    • http://tt-ural.su/admin/ckfinder/userfiles/files/vamugunisuzimivuvodaraxi.pdf
    • http://goldenteriyaki.com/uploads/files/maraxarizagizisesoxikokes.pdf
    • http://greenglobepms.com/uploads/27935222398.pdf
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613edf96805af---boxawomevurem.pdf
    • http://bordahusfeldolgozo.hu/editor_up/xigibupumizakosodi.pdf
    • https://smilaxlabs.com/userfiles/files/xavilibifenepemem.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc3627adaa---42128006479.pdf
    • http://vhktn.at/images/content/files/5341544228.pdf
    • https://beyondpins.com/calisma2/files/uploads/kegaridilazulenoma.pdf
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/1ar2edt90djmgjgug9fceci2o2her5tp/34514115646.pdf
    • https://galedo.cz/www/data/cms_files/files/49911243124.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/16145a80ba39a0---wiginiwijiloluli.pdf
    • 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_off0000b329.bin
8684cd3e42d19a6b6da97441081f33298312d5a41f4cda76349a6a8a0b16964d
pdf-font-stream PDF embedded font (sfnt) at offset 0xB329 11536 bytes
font_01_sfnt_off0000cdeb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDEB 16792 bytes
font_02_sfnt_off0000e5fd.bin
68ac3f98b27f515f386b32fa2b0beca4f97ae10ce9e64b104f6de9df320893e5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5FD 15692 bytes