Malicious PDF — malware analysis report

Static analysis result for SHA-256 636d3c87039076d9…

MALICIOUS

PDF

88.6 KB Created: 2021-07-14 00:08:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: 85b038de7bc2e2598b82c94f56bd7355 SHA-1: 38ab12a59a89b46615d1df1a71c2e4bd08472840 SHA-256: 636d3c87039076d914ebef2526b47aa32f7ebf77261c4174c5143fba1c0e8f64
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress upload storage, suggesting it's used to distribute further malicious content or phish users. The presence of numerous unknown URLs reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/en5lv08bb46q93llic9ut2gdm5/dezibolufezi.pdf In PDF document text
    • https://fedico.ca/upload/editor/file/12820401235.pdfIn PDF document text
    • http://vetranhtuong.info/luutru/files/92619040584.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/kenejamorisewipol.pdfIn PDF document text
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/nfq5rv1iiam54lvk6h9unif5it/47165068165.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609beb7bbd0f2---daleviziwezafepemarifono.pdfIn PDF document text
    • http://wo-kop.pl/userfiles/file/70949803009.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d3c715b815---22171177661.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/21cd77a213cdb9ef9fffb09360af55f7/tibixakinadujag.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608c6aa18410f---70328960315.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160895d1631cf4---88583471004.pdfIn PDF document text
    • http://savitapiti.org/ckfinder/userfiles/files/25159419071.pdfIn PDF document text
    • https://infravoip.com/wp-content/plugins/super-forms/uploads/php/files/7e3aab9955ee93e1c277ab312de801bd/xufigoroxul.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607efa7eb1ced---taberinusodipo.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd2597aa140---26048129136.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a7d8ecbbd43---wekumudulefuz.pdfIn PDF document text
    • http://yjccnc.com/upload/files/wegepesareg.pdfIn PDF document text
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/c124497662c23486ad0b3a3500676f7b/3309818482.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/c2d260b05479c6e3e03a29f8caadc5e2/44141838501.pdfIn PDF document text
    • https://tosto.cl/ckfinder/userfiles/files/megidubidatuworijet.pdfIn PDF document text
    • http://esejsc.com/upload/files/17842758881.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=sunset+and+moonrisePDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e86a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE86A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10077 2652 bytes
SHA-256: 30784ae0098436fe876fc5904b0ed717d35cf1d153b2f2c544541d18cefa6e79
font_02_sfnt_off00010b9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B9F 18216 bytes
SHA-256: 0c0dfa3de441848c687266c53cfb9a01011485f6f06ddfad5c9c89adf69fffef
font_03_sfnt_off00013b77.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B77 10540 bytes
SHA-256: c96ff22f608e943385ee3ed9f4f7fbd44f60981c2ce839180bf4e3e1b9b9bcfe