Malicious PDF — malware analysis report

Static analysis result for SHA-256 825f5dac43daef4a…

MALICIOUS

PDF

80.7 KB Created: 2021-09-13 01:31:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f5e837e0783dd42b560713ee4b5b4462 SHA-1: b7bd9457af19b3c64bb51b992dbcd4e38bb49c62 SHA-256: 825f5dac43daef4a8add11c1acb72d125e5970cecd83d2e7633239fbb8f76131
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains embedded JavaScript and multiple external URIs, indicating an attempt to redirect the user to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests the document's purpose is to host a large number of links, likely for phishing or malware distribution. The ML classifier and ClamAV detection further support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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
  • 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.
  • 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://wastran.ru/uplcv?utm_term=kof+vpn+apk+download PDF link annotation
    • http://drairtools.com/ckfinder/userfiles/files/91451479566.pdfIn PDF document text
    • http://addon-colsman.somantec.net/ckfinder/userfiles/files/togap.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/sojugofekenex.pdfIn PDF document text
    • https://alcoquimicos.com/ckfinder/userfiles/files/gexuwozifiluguvaxewawo.pdfIn PDF document text
    • http://effektfilm.de/files/file/34287999890.pdfIn PDF document text
    • https://whitesal.com/data/images/file/7349_20210905111524.pdfIn PDF document text
    • http://garant-fond.ru/ckeditor/ckfinder/userfiles/Images/files/batiboguxoferakumuzu.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/84757802379.pdfIn PDF document text
    • http://desiaussies.com/ckeditor/uploads/files/37751296220.pdfIn PDF document text
    • https://mehreganimaging.ir/images/upload/files/soxiwosuximigibizudulal.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/kezedixuxowabelanolisizi.pdfIn PDF document text
    • http://rosritual.su/app/webroot/js/ckfinder/userfiles/files/60798631182.pdfIn PDF document text
    • https://ever-progress.com/upload/files/rijivuwuxusup.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/mavavulosazudizezetuzaje.pdfIn PDF document text
    • http://tajilin.com/upload/files/razoxesamijod.pdfIn PDF document text
    • http://www.ecrivains-consult.fr/easyonline/ckfinder/userfiles/files/dafaviwomunowaxesuzem.pdfIn PDF document text
    • http://locnuocvietmy.com/Images_upload/files/53691994699.pdfIn PDF document text
    • http://steffis-strassladen.de/userfiles/file/90032508827.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/rojanukanako.pdfIn PDF document text
    • http://eclickapps.in/userfiles/files/99027029752.pdfIn PDF document text
    • http://itps-group.com/uploadfiles/file/xagidogef.pdfIn PDF document text
    • https://www.hkha.org/ckfinder/userfiles/files/sutexazuxuwajebikukek.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c801c7d975---sekufakaxizopisebuletez.pdfIn PDF document text
    • http://pzhjintai.com/upload/files/fezonenu.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bf7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF7F 10136 bytes
SHA-256: c546dfc4ee012431134a61159881e7a7bd5a097b4466afb47a2c05f740ead22b
font_01_sfnt_off0000d64d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD64D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE5E 16148 bytes
SHA-256: b17e3c388ca520c70044df51a505a8c8de3d1ca9b2e495c629779bc8d31aca59
font_03_sfnt_off000103e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103E9 18620 bytes
SHA-256: 9ba887042aae883f764a1d41adf3f2ea8d6e2940b7f81d92b7cf5631a0adca9a