Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1d982a266e190a6…

MALICIOUS

PDF

95.5 KB Created: 2021-07-05 01:01:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0091eb748105c2a8bbdafc5e9788ab12 SHA-1: ed89c66fc5a9a75ed6948ffd6538b4595f4cd5bc SHA-256: a1d982a266e190a6eb9ccd67c12d219499e6409d1f8d5c0a1c3c5604b161d2f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated, preventing a clear understanding of its immediate purpose, but the overall structure and URL distribution strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=letter+from+birmingham+jail+pdf+annotated
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0c5c12191e---zudoretuwifuxofinivale.pdf
    • http://machinegroup.ru/img/outer/files/23530283874.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/52csovke91rjb1bsphjammdmmv/43450957091.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070619fcd441---93807874513.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160adaf13538c0---zinugemutezuwiboxugav.pdf
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5606ba96e9---taraxexuvakagokusipi.pdf
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/lbr8rm31rpj01u8b3a6kvqejph/witawizinuxifi.pdf
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/429cdc1f5221a82f98722f7dd0803513/tutukixesaliwopase.pdf
    • http://wienbildarchiv.com/upload_files/files/jagozopiniwobe.pdf
    • https://bishopsalamatkhokhar.org/userfiles/file/lununaro.pdf
    • http://gmkms.net/upfile_editor/2021/files/wugoludowelew.pdf
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd724f179f---11358479335.pdf
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160aac09b00ed4---10975448153.pdf
    • http://bayzones.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/vavudozelubidoruvus.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a65bfca23a1---1522951835.pdf
    • http://ongnuocdenhat.com/upload/files/30632649360.pdf
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/f18951ee7f514db320cf08734841af7f/94849522365.pdf
    • http://goldenpeak.it/userfiles/files/38310756363.pdf
    • http://luyenthidhcanhsat.com/Images_upload/files/21955295716.pdf
    • http://ordineveterinarivenezia.eu/userfiles/files/sijinefukelewisoduvi.pdf
    • https://nikoljski.com/ckfinder/userfiles/files/pejugevijotavog.pdf
    • http://praguetransfer.com/files/file/37452997623.pdf
    • http://nt-module.ru/ckfinder/userfiles/files/midavulikedegewimolojudal.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_off00011185.bin
a7385dc8b2db67a078bc836476d128d6e78d385b2caf08c2292516d5aee5ebde
pdf-font-stream PDF embedded font (sfnt) at offset 0x11185 17744 bytes
font_01_sfnt_off00013fab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FAB 16792 bytes
font_02_sfnt_off000157c2.bin
1e1cdd3e921aa6df68337c522d1b69b4afbc6227689450d4a72c4de1cb09fd44
pdf-font-stream PDF embedded font (sfnt) at offset 0x157C2 11004 bytes