Malicious PDF — malware analysis report

Static analysis result for SHA-256 639f1bb8aa5688df…

MALICIOUS

PDF

82.2 KB Created: 2021-09-21 07:42:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 95629219b72210c8d82802b132125358 SHA-1: 3925c5cbef3454a1018e908f6036786ef4322088 SHA-256: 639f1bb8aa5688df6b7e15417688b953eb5cb433fec5555c7f5d8c7b397d4387
172 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external links, with several heuristics indicating a link farm on compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing a second-stage payload. The presence of a visual download button further supports a lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • 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.
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://franceplus.fr/userfiles/file/josutekobijulupabirike.pdf In PDF document text
    • http://www.bash.cl/media/file/78185244193.pdfIn PDF document text
    • https://openkomm.yussfone-crm.com/userfiles/file/33010198529.pdfIn PDF document text
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/xezetevugokipudiropovifol.pdfIn PDF document text
    • http://www.llmhospital.com/www/js/ckfinder/userfiles/files/82605860980.pdfIn PDF document text
    • http://imdad-egypt.com/userfiles/file/wupufidomifopimevexotena.pdfIn PDF document text
    • https://markmont.eu/editor_uploads/system/files/78943963611.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/40367577070.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/6348820126.pdfIn PDF document text
    • https://kvizek.hu/ckfinder/userfiles/files/19355582504.pdfIn PDF document text
    • http://oilspecchem.com/files/ladivalujepijiri.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/161433128053fa---26570526799.pdfIn PDF document text
    • https://coil.hk/upload/files/begurasesoxadeba.pdfIn PDF document text
    • https://bearings.vn/images/ckeditor/files/39465428573.pdfIn PDF document text
    • http://worshipedia.net/sites/default/files/file/lobibazav.pdfIn PDF document text
    • http://medicalproduct.hu/images/files/zikoxogivaloxegupojudi.pdfIn PDF document text
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/79625488814.pdfIn PDF document text
    • http://azizolace.cz/images/file/42786569219.pdfIn PDF document text
    • https://kaowei.tw/image/files/20210916_173555.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/cbd9c5df689a9f04c0613eafd95f2900/50241448688.pdfIn PDF document text
    • https://hunghiephuylog.com/upload/files/kuvoxomo.pdfIn PDF document text
    • http://medicare-darmstadt.de/bilder/UserImages/file/38840273640.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/c26af041f70373d9e8b8630d371a0da6/55421204786.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=pokemon+emerald+randomizer+rom+download+gbaPDF 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_off0000db40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB40 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f352.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF352 18092 bytes
SHA-256: c12c8c4ceeb3493026603a48ced6a5680801ff2868c3662aee711a739f6c34c7
font_02_sfnt_off00012282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12282 10704 bytes
SHA-256: 4cb57bc71858728930ad7774c474c1263f722277b7729d1f63c826ef64bcc863