Malicious PDF — malware analysis report

Static analysis result for SHA-256 85f9f89963ff9988…

MALICIOUS

PDF

89.4 KB Created: 2021-06-20 12:10:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 07c72bd27516f2ae3de050d15740837d SHA-1: 44907d05d377afa207d247b55f79b0e7da2f0440 SHA-256: 85f9f89963ff99884574b8cec679ff7cd81430fe7d51de344ea0737c8041b94d
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The presence of these links and the overall structure strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://isosklo.cz./uploads/43912223880.pdf In PDF document text
    • http://valeneighbors.com/userimages/94331812770.pdfIn PDF document text
    • http://romanakladatelstvi.cz/userfiles/file/ragunafojeranus.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086b9d039283---18852804670.pdfIn PDF document text
    • http://cnex.cc/images/blog//file/limitigiwovuwoso.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1609684d82c8b9---todaroxulonufesipegek.pdfIn PDF document text
    • http://amdind.com/userfiles/file/nizagapuvepijaz.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/zuwagekisur.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608770b297dac---95242492169.pdfIn PDF document text
    • https://betibg.eu/webroot/img/files/98375116286.pdfIn PDF document text
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079dabae6778---zavalinekugotud.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/q7pk2qg966i6k8ns036jkt63ri/nofatoj.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/clom0mq72crt9jgdonlkck99i8/vufozojuraxolidez.pdfIn PDF document text
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/ee05df2b9092406cc747f4a9556e6ec9/gafetexa.pdfIn PDF document text
    • http://normel.org/files/upload/file/gefonawafiven.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083e90fa0e07---89567180657.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/437c5154f36f3dc11a55accf7f8a8cdc/kasikenaseletibejij.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f23ea06100---98076202213.pdfIn PDF document text
    • http://nutronicltd.com/userfiles/file/pefoxinuzat.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=inverse+of+a+square+rootPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011f63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F63 4852 bytes
SHA-256: e4eadbc4260b7239b11bf83dacab2cd509bef1dbffc91ac51047c5604c30e13b
font_01_sfnt_off00013000.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13000 11512 bytes
SHA-256: 8d4c275ebef4ea590e337e28fccf73b8148f91d830e1f6715ca0e896052d3244