Malicious PDF — malware analysis report

Static analysis result for SHA-256 1dcf46b03c9aabc1…

MALICIOUS

PDF

77.0 KB Created: 2021-06-11 01:31:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 12422d66da7abb7d7218005941ed8cd4 SHA-1: cc1428b682fffb41243f7642f999ae5f39688339 SHA-256: 1dcf46b03c9aabc1df9b685811ce8a414d18d4bbc213714cb63594089bfeeb1e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised WordPress sites, suggesting a link farm or phishing lure. The presence of PDF-specific heuristics like 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the document is designed to redirect users to potentially harmful content.

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://archism.ru/uplcv?utm_term=operating+systems+concepts+10th+edition+solutions
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160801b17a7a72---keforew.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7f32a9bbf3---27012320381.pdf
    • http://english-island.pl/wp-content/plugins/super-forms/uploads/php/files/afqnualum279mabqrs2fvv66v5/zuzebogetudizevaletilofof.pdf
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160804d199a450---22120294775.pdf
    • http://psychoterapia-przemysl.net/img/userfiles/file/jatud.pdf
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/a054369f7ee8a636bcdc4d3b08ddaf25/zalireminulexep.pdf
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160c28d6eadfc8---63044014451.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/08b36fcb1387214b5bc2f6733ec56bef/wozuzofovubugu.pdf
    • https://www.etbsupplies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4e5dcda6e0---pizewakiforamax.pdf
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a41e132d7eb---41812720048.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/b175e0b4009508c73d0de9044183660b/lomepivamirijew.pdf
    • http://mppscstudy.com/admin/usercontent/file/durop.pdf
    • https://tlproduct.com/userfiles/file/tazudofotepimunekixusuzab.pdf
    • http://bioident.pl/photos_fck/file/junuvesubimivixezakej.pdf
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/6e5c454c8e4a32f96db218a2e1d210b3/57793142264.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/vd86ck0thft8pr8nuv9ln1ub7u/xizetojedirifavejififol.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/d24a45cc012e46aef704ea74287c558b/69469836934.pdf
    • https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/078a8575e8ccf0344c25d59979635b36/96620049532.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ecea.bin
88bfbeaa81331cf120e9350fab8e6f33fcb33ff7bfa38d7a81afee83dafd8914
pdf-font-stream PDF embedded font (sfnt) at offset 0xECEA 5808 bytes
font_01_sfnt_off0001008d.bin
f94599c47d043bbea03c14fb79874931bc32702a7dd2e997a1253ce822d1c4eb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1008D 11084 bytes