Malicious PDF — malware analysis report

Static analysis result for SHA-256 a953f840c8954316…

MALICIOUS

PDF

69.8 KB Created: 2021-09-25 12:14:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ec953db1f4470db5da88f5d373b9e241 SHA-1: 499645a31cd0e2dac6e469e7954aac76db91d8c3 SHA-256: a953f840c895431677791916cdac2b7daaf5d56f82cefecd8c0241d385e6f323
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to lure users to potentially malicious destinations. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the nature of the URLs and the detection results point towards a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://archism.ru/uplcv?utm_term=develop+android+app+on+mac PDF link annotation
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161316bcdcc808---43045278285.pdfIn PDF document text
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/92581848286.pdfIn PDF document text
    • http://floral-design-lindgens.de/userfiles/file/mimavuluw.pdfIn PDF document text
    • http://archpiudue.com/userfiles/files/tepudesoju.pdfIn PDF document text
    • https://dcmheavyequipment.com/admin/images/file/92096570807.pdfIn PDF document text
    • https://krantiservice.com/ckfinder/userfiles/files/satidakakufupeze.pdfIn PDF document text
    • http://rileyillustration.com/images/agency/files/suvadazoget.pdfIn PDF document text
    • https://mondoaudio.it/img/uploaded/file/81963506553.pdfIn PDF document text
    • http://only-svet.ru/upload/files/47971947492.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/780234b07db8ed235b0cbfa83064fcf2/58831067820.pdfIn PDF document text
    • https://nangluongvada.com/uploads/files/20067773765.pdfIn PDF document text
    • https://www.sacict.or.th/ckfinder/userfiles/files/jorovujidusufub.pdfIn PDF document text
    • https://deycaterers.com/ckfinder/userfiles/files/45394360605.pdfIn PDF document text
    • https://fonixkoncert.hu/upload/file/83743110061.pdfIn PDF document text
    • https://amoslodge10.org/ckfinder/userfiles/files/jupege.pdfIn PDF document text
    • http://baliretreatcenter.com/olabali_ci/media/images/newsfiles/85660637676.pdfIn PDF document text
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/e64c7684126d14063cf0b37cc3c1c400/4797179078.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/48vuv3otmrch7nsfqup7eka330/7490711557.pdfIn PDF document text
    • https://wineart.online/userfiles/file/virinun.pdfIn PDF document text
    • https://sausalito.com/wysiwygfiles/file/36129986420.pdfIn PDF document text
    • http://audidalys.lt/ckfinder/userfiles/files/gepub.pdfIn PDF document text
    • https://portofcrotone.com/dati/upload/file/pakidagulegadixi.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/wezimifuv.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/rowufonasinegokivuboti.pdfIn PDF document text
    • http://smartraoptics.com/fck_filemanager_upload/file/rulajoritutetozivemitudul.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_off0000b39f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB39F 10476 bytes
SHA-256: 3ca5868dafc917098771b73899a973c7b846450345339de6fc990ddb56158ed7
font_01_sfnt_off0000cb52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB52 15228 bytes
SHA-256: bee2d147cb13e9ad1d3b64968e3d355634e5efedc47dc7c79403c6e5c48ca631
font_02_sfnt_off0000f11b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF11B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1