Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4f9641136a020aa…

MALICIOUS

PDF

209.2 KB Created: 2021-10-07 23:20:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 3a349a7705013f1d8fde965982c1a779 SHA-1: ad70e88d50b63ce15f6c9dfbf1155df109b1200d SHA-256: b4f9641136a020aaf4cf163d86f5a5d29d4bb700523a8b3f698b85602f9b9842
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for delivering malicious payloads. The PDF also contains numerous external URIs, many of which point to compromised WordPress sites, suggesting an attempt to host malicious content or redirect users to phishing sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9806

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://smidgel.ru/uplcv?utm_term=the+founding+playwright+of+the+realist+era+was PDF link annotation
    • http://nc-israel.ru/upload/files/viputanerokigolagiwinuv.pdfIn PDF document text
    • http://aaas.handyfriendship.com/upload/files/75438254781.pdfIn PDF document text
    • https://fereshtegan.net/basefile/fereshtegannet/files/2218652049.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16155a5bb9f6b2---94345839264.pdfIn PDF document text
    • http://kolesa.sk/files/59057123038.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/zefedekudigarufod.pdfIn PDF document text
    • https://membermimpi.com/contents/files/90159142592.pdfIn PDF document text
    • http://jkbprivateiti.com/userfiles/file/48430619497.pdfIn PDF document text
    • http://netcentricnj.com/ckfinder/userfiles/files/20655568858.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/85114737826.pdfIn PDF document text
    • http://burningspearmarketplace.com/js/ckfinder/userfiles/files/68228754011.pdfIn PDF document text
    • http://seamacros.com/upload/file/31611278998.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202194136496537.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/8v7522omiu5peb3t9o4o84papk/44257940561.pdfIn PDF document text
    • http://mudrkanuch.sk/editor_uploads/system/files/xikagikikagigabulimukige.pdfIn PDF document text
    • http://garage-ys.info/js/upload/files/kazudiwalekuxerikize.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/da38b6908e65d7ae9bdbc8ed0b47b701/6062222636.pdfIn PDF document text
    • http://take114.kr/FileData/ckfinder/files/20211003_32BE49E84829ED5C.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/sodekoxuwilolunijibu.pdfIn PDF document text
    • https://testpensija.bankai.lv/ckfinder/userfiles/files/82191911573.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c4cd134267---vonidezezejibire.pdfIn PDF document text
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1615e81427072d---55845092458.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/27668572631.pdfIn PDF document text
    • 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_off0002ce80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2CE80 11040 bytes
SHA-256: 3644b420b8fc412409a0dabf718480f81456c11e785abaf32a4dc81777894818
font_01_sfnt_off0002e7ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2E7FF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00030011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x30011 21324 bytes
SHA-256: fce1bda42d8793fb771995bc21d62fe1af66f9ed9808bd548801523d9248aacc