Malicious PDF — malware analysis report

Static analysis result for SHA-256 39ce50b4f3516695…

MALICIOUS

PDF

93.3 KB Created: 2021-07-01 20:49:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 4350bba7a6d79da36df28d1d54568f50 SHA-1: 13fde293724f749917449d6dc700325a2bc1b238 SHA-256: 39ce50b4f3516695b60b931cc50479d120d4fa7db28f78ff64e8f904a47c5193
176 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised WordPress upload directories. The document body is heavily obfuscated, but the presence of numerous embedded URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic suggest a primary goal of redirecting users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) or Microsoft license-boilerplate documents that carry no urgency or charge/dispute escalation.
  • 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://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bfeb57d50e3---jemofezasevu.pdf In PDF document text
    • http://grandchainfamilyfoundation.org/clients/85333/File/jinivamuvefaxakomuxoti.pdfIn PDF document text
    • https://zhansq.cn/upload/file/towoxubu.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1839d3ad86---wowemupovuzorubiduziratip.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/daf209d36a68cf0efbcd415e144db721/dedovunawugomobabaladuka.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c882919bc83---poganirunal.pdfIn PDF document text
    • https://powermailer.in/userfiles/file/gamosibojuvuza.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/dopamefovaxutozi.pdfIn PDF document text
    • https://arizonalightingsales.com/wp-content/plugins/super-forms/uploads/php/files/c62467d0c0f975f7f1a19ae4f8eee289/nozoromulirebizosumuziz.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f061be191e---tovexoveguw.pdfIn PDF document text
    • http://englishplanet.info/ckfinder/userfiles/files/9914711411.pdfIn PDF document text
    • https://fertilizergranulatorprice.com/d/files/vapufowafeduzozobozopabo.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/zovederofitar.pdfIn PDF document text
    • http://apcmagon.com/userfiles/22973097193.pdfIn PDF document text
    • http://chanakol.com/ckfinder/userfiles/files/sapilofejumazexerevimora.pdfIn PDF document text
    • https://vntdc.com/upload/fck/file/jujuzufifizufo.pdfIn PDF document text
    • https://sherwoodchamber.org/ckfinder/userfiles/files/54764534398.pdfIn PDF document text
    • https://balbok.net/admin/ckfinder/userfiles/files/48126247189.pdfIn PDF document text
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608200d501200---39960133686.pdfIn PDF document text
    • https://termoformat.md/img/files/69140710805.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/vtidhpfi51qhvjkaq71d60ckk4/rodopovugujimunewanim.pdfIn PDF document text
    • https://gfow.om/wp-content/plugins/super-forms/uploads/php/files/lj2aqe6tt71hcta1pet9r8ib0m/58297004098.pdfIn PDF document text
    • http://novichiha.ru/pic/file/mimelisibapa.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/44950898289.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=poultry+loan+project+reportPDF link annotation
    • 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_off000105d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105D7 10452 bytes
SHA-256: 47e274a9d85b738d0f2029bb0eef5926c210941f9d14f71d4fe38fc0d7b0c682
font_01_sfnt_off00011dc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DC5 18624 bytes
SHA-256: 6fdedb30c498d6bd63699cd88ad4ad70f9cd5de4854af79ed986d98ba08deb37
font_02_sfnt_off00014e5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14E5D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1