Malicious PDF — malware analysis report

Static analysis result for SHA-256 efcca83381ea9a48…

MALICIOUS

PDF

93.6 KB Created: 2021-07-31 09:49:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 249057691f8fbaee5d4eabdad7ed517e SHA-1: 2f769610adfeac8065eba0a3b1db5cd12384ca9d SHA-256: efcca83381ea9a48abb2c9d7036949b59cde5b46b79cafd3ff39464012602f80
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to potentially compromised websites or disposable hosting, suggesting an attempt to lure users to malicious content. No scripts were extracted, but the presence of many external links indicates a primary function of redirecting users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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://oniceh.ru/uplcv?utm_term=exercice+physique+chimie+college+3eme+pdf PDF link annotation
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160725ac9c2a1e---93993700460.pdfIn PDF document text
    • http://viral-list-machine.com/ckfinder/userfiles/publics/files/1247207605.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/sufofilutorodoritelovika.pdfIn PDF document text
    • https://powermailer.in/userfiles/file/17912290771.pdfIn PDF document text
    • http://klefmarken.se/upload/file/35137316595.pdfIn PDF document text
    • http://aiskreunion.com/clients/b/b4/b417c2091670ce0b0d78f4b231aea02c/File/pejivifime.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608113bedf995---26001231262.pdfIn PDF document text
    • http://apartmaji-zunicmile.com/uporabnik/file/doxokepejujukozixakuw.pdfIn PDF document text
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/69f2c59c4877f1a3fa9e9d0b0f6ba7de/5821539771.pdfIn PDF document text
    • http://simmsfamilyreunion.com/clients/9/98/98d47f1658d09d39d77ba56043454c9c/File/9256807720.pdfIn PDF document text
    • http://vhktn.at/images/content/files/tomusakogej.pdfIn PDF document text
    • https://dianthusindustrial.com/resimler/files/79089809545.pdfIn PDF document text
    • http://bigxra.com/uploadfile/file/2021062801070773499.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071f5b70b958---43515308789.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbe5a0c715---29877496729.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/adbd7758a48fed8861ea245650785006/mesajisusabotabeva.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/eacc6e9abf1b02d56af08fdf6d4fb282/73542657184.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/865e3cba27c75c6d2894d5c2838c2dca/dusol.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608a77304b59a---nusomuxiradowamujerag.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160873dbb32e99---69260553075.pdfIn PDF document text
    • http://hum-lucknow.org/test/fckeditor/file/xibugejadugedine.pdfIn PDF document text
    • http://jongauger.com/ckfinder/userfiles/files/vizarapavoxafe.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/nugimuvalokabulevanago.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/e8c35ba0ec44ee78db176e756b3582f9/rikuvusevaleg.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_off000103b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B4 19132 bytes
SHA-256: 19574ae3f11e81803d8b699e268ccdc8c39b8735fcd4f821e96f0db90c780415
font_01_sfnt_off000133d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133D0 11320 bytes
SHA-256: e580617bf483eb3a97ee14420c9f4e78968fbe3df0e78c928b67ce1fa3f832b7
font_02_sfnt_off00014df4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1