Malicious PDF — malware analysis report

Static analysis result for SHA-256 59c5f675789bfc21…

MALICIOUS

PDF

86.5 KB Created: 2021-07-26 10:48:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3ceabfdc6dc7c5ad1b6b922a4b54d76c SHA-1: ec9f5df26823ce2561e0438811fc92701abee2e8 SHA-256: 59c5f675789bfc214ba3fe3e8fab12b6a7eabff43a5377ea952d6a3d0652690d
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and does not provide direct clues, but the link farm structure is a common tactic for such attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/71ea5cdc675258fbb56d150e4222dc74/16239142802.pdf In PDF document text
    • https://macauroommate.com/ckfinder/userfiles/files/16030297799.pdfIn PDF document text
    • http://laptopcuhaiphong.vn/upload/files/tudivopupuj.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f5cc344c3a---gimeroviredupurexipowisip.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/2bad88e21faac545aeb0445568dc0056/darapizubolebiw.pdfIn PDF document text
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c89a811f86b---mapaloletepebulev.pdfIn PDF document text
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/taibnp2eh1cn2al5gjtgaujao3/2320267792.pdfIn PDF document text
    • http://hk-dcc.com/wp-content/plugins/super-forms/uploads/php/files/58m1jpda0fb711dmakolbgbmbj/61524502116.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a40699776bf---vikidiwoxafiwoven.pdfIn PDF document text
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/3jc7ciqh8rjn6lce33s37im0eo/negojakoxigekoverolawik.pdfIn PDF document text
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/16096ed8ae0dd2---59651446780.pdfIn PDF document text
    • https://alphacleanwashing.com/wp-content/plugins/super-forms/uploads/php/files/aeb40fef32f9682e216be343d3348aa6/56970285608.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/vuxamuwodabibozik.pdfIn PDF document text
    • http://archiprojektai.lt/app/webroot/uploads/userfiles/files/23796856960.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091b535ee02d---xiputozipimu.pdfIn PDF document text
    • https://maribon.net/app/webroot/files/userfiles/files/72334902019.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/kobujajarop.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/df7f7d4a1f7660c819a2e57c49d03f3e/32989060708.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609f6a53df136---15533489346.pdfIn PDF document text
    • http://minuspk.ru/minuspk.ru/userfiles/file/71818398396.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160de6a212310a---dibovapo.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16083f05bb02be---59155367991.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=northeast+mississippi+community+college+basketball+twitterPDF 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_off0000ec99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC99 11332 bytes
SHA-256: 95c478cd74da219358237d7cfc23ebee5e4f90df1156ae334546190274bda2da
font_01_sfnt_off000106fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F0C 16640 bytes
SHA-256: 3f03d316bb8442a0e92fb1c6dc7ebbab995fc54a9868c1ed94ce81654ed83fd8