Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4a5dabc9a48880d…

MALICIOUS

PDF

87.2 KB Created: 2021-06-29 08:20:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1e880e85b9de379227cc264df819e262 SHA-1: 1de88fcfb1d7a4c0f763ef34a368549afccc6dde SHA-256: b4a5dabc9a48880dfb81ca1b9a15f99a2e6457efffe0a8e5e53f354a03557879
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The primary attack pattern involves exploiting users through these links, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://synerhu.ru/uplcv?utm_term=bank+management+trainee+interview+questions+and+answers
    • http://ztkammer.at/uploads/file/33801727770.pdf
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/6e9ef09890844fe3799b2230f80f18be/64939114340.pdf
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fd8b019f11---zorisoluwo.pdf
    • http://schs1968.com/clients/861610/File/39358359211.pdf
    • http://pwr-tech.ru/userfiles/file/fobizuruponanuborimudiweb.pdf
    • http://wamer.org/userfiles/file/jelajefutida.pdf
    • http://www.lugashotel.com/data/editorfile/93826689887.pdf
    • http://arlingtonhigh1961.com/clients/e/ef/ef36f0800c0a5d5a0b00d5ecc8c3c6da/File/67297699990.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094151bf3890---40368210563.pdf
    • http://matsusushionline.com/uploads/files/gazogoj.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/8bd3129f9b3c8577aba445c698817783/jesunimenifasafevamenaxa.pdf
    • http://dynamic1984.com/user_file/file/wedakukutitazorukos.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ab7829a8ea---zatafutuxu.pdf
    • http://eau-msu.ru/ckfinder/userfiles/files/18222967698.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/0f0dpnj37213dqj189g10549d0/zunonig.pdf
    • http://www.gabrielamaciel.net/images/content/file/vovavinanobuze.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bea2ed38382---1735800214.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac50cd575bb---derutitebuwoninidopejago.pdf
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1609bc00b323cc---22649527136.pdf
    • https://webmenuplus.com/images/file/migavudobokujojebozegoxut.pdf
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/pe1kbima96qohm92c7vja9c3ed/mopumawusepugafixip.pdf
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/91b2e2df549dedc2ada4d4e0564905aa/52166843711.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_off0000f1e5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E5 16792 bytes
font_01_sfnt_off000109f7.bin
670dc1e1bda46c487bb3cf82a875b393f27bd405e0cf3c80d5e43b00363cdf03
pdf-font-stream PDF embedded font (sfnt) at offset 0x109F7 17008 bytes
font_02_sfnt_off000135d9.bin
2fe0fc5ada7831be89f12e67cf7188d24f75e3d7573e0f2c8d25bf2bf40268be
pdf-font-stream PDF embedded font (sfnt) at offset 0x135D9 11088 bytes