Malicious PDF — malware analysis report

Static analysis result for SHA-256 9834a9da40441656…

MALICIOUS

PDF

77.7 KB Created: 2021-09-11 14:37:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d4c62a06d1b081c9ff46cb09ebbcdd7c SHA-1: 39e2ab09f746c5d97e507f8b401a201f0f0b75f1 SHA-256: 9834a9da4044165663f431674a5782bbf550d0a7225811f9082c16b08cb57bbb
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to host numerous links on disposable domains, a common tactic for phishing or distributing further malware. The embedded URLs point to various PDF files hosted on potentially compromised or malicious sites, reinforcing the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://postele-z-masivu.sk/ckfinder/userfiles/files/fiforuvolaxikanuz.pdf In PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba43a45802---49281088821.pdfIn PDF document text
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/42334646376.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/88176579517.pdfIn PDF document text
    • http://appli-veolia.net/ckfinder/userfiles/files/61548276332.pdfIn PDF document text
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/zelotisudiv.pdfIn PDF document text
    • http://gyogytornasz.hu/editor_up/77684426474.pdfIn PDF document text
    • http://imapbook.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/genavaxitafaga.pdfIn PDF document text
    • https://pachetedeturism.ro/images/files/rujodapi.pdfIn PDF document text
    • https://cuatudongbinhduong.net/uploads/files/nutanunabagivojabuz.pdfIn PDF document text
    • http://jin16888.com/userfiles/file/12524787444.pdfIn PDF document text
    • http://hasicimosnov.cz/foto/Image/file/nijimikivaturilegapamejuv.pdfIn PDF document text
    • http://yuemeism.com/uploadfiles/files/6419950226.pdfIn PDF document text
    • https://hssanesteban.cl/files/joxosugefewek.pdfIn PDF document text
    • https://karaari.leaddeehub.com/userfiles/files/tolipaze.pdfIn PDF document text
    • http://ducthanggroup.com/webroot/img/files/21597068360.pdfIn PDF document text
    • http://jmk.kr/ckfinder/userfiles/files/wunuwupinifipusigoloses.pdfIn PDF document text
    • http://carnavaldemarbella.com/Senegal_5/Content/files/userfiles/file/puxazelima.pdfIn PDF document text
    • http://kovofilm.cz/userfiles/file/nalipojidokevobawajivojij.pdfIn PDF document text
    • http://www.rolstoellift.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf50961917---wexonaditiberimoped.pdfIn PDF document text
    • http://bxbrdh.marketsearching.com/upload/files/tevuvosuv.pdfIn PDF document text
    • http://nakamurasangyou.jp/app/webroot/uploads/files/79754595035.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/92179476764.pdfIn PDF document text
    • http://metamorfozyayincilik.com/userfiles/file/fexoxagev.pdfIn PDF document text
    • https://luatsuavina.com/userfiles/file/kozuforumupegabonuwuxor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=game+hacker+apk+downloadPDF 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_off0000cb7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB7A 17720 bytes
SHA-256: 0affb5a6227c19f43261627c31058b83e1116afff521c5d8fd76b95ccc496d2f
font_01_sfnt_off0000f911.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF911 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011128.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11128 10640 bytes
SHA-256: 5d93d53624aabe4d71461755381b2c29bd1637a6beebb47e2a40078d8b7bb678