Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a415bdc00936957…

MALICIOUS

PDF

71.5 KB Created: 2021-09-26 01:50:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d0793b7b05407b0023c394036d8f565e SHA-1: 0e259236c3dba022256596fb75d6f45fd4374459 SHA-256: 3a415bdc0093695734a7beeeb43f84a712948cd498790abb8efc0229abf03214
126 Risk Score

Malware Insights

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

The file was detected by ClamAV as 'Pdf.Phishing.Trojan' and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating the PDF is designed to host many links on disposable domains. The presence of external URIs and the overall structure point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://msslink.ru/userfiles/files/50127221442.pdf In PDF document text
    • http://surinmajestic.com/phya/ckfinder/userfiles/files/21123892240.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/45962888162.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/nenasobesolatawiwibes.pdfIn PDF document text
    • https://www.hkha.com.hk/ckfinder/userfiles/files/lelotedasimaw.pdfIn PDF document text
    • https://gionggiacam.gagiongvitgiong.com/ckfinder/userfiles/files/43408570482.pdfIn PDF document text
    • http://ttfi.org/app/webroot/userfiles/file/dunulefuverokuzikejuwaden.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/togugekatuzofilot.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/42619330680.pdfIn PDF document text
    • http://automyjka.pl/automyjka.pl/userfiles/file/vafimotamowopobipamam.pdfIn PDF document text
    • https://eurochen.com/UpFiles/WebEditorFiles/file/31471485295.pdfIn PDF document text
    • http://namjapizza.com/app/webroot/files/xipotaxusuveba.pdfIn PDF document text
    • https://abcelectricalonlineshop.brilliantwebtech.com/userfiles/files/64019432508.pdfIn PDF document text
    • http://kepco-group.com/uploaded_files/userfiles/files/34372206026.pdfIn PDF document text
    • http://evola.it/userfiles/files/9942598240.pdfIn PDF document text
    • http://sallytour.com/FileData/ckfinder/files/20210901_A0E24A4D9CB932FD.pdfIn PDF document text
    • http://norilskgu.ru/userfiles/file/25321338665.pdfIn PDF document text
    • http://gioiacompany.net/images/upload/file/46433377555.pdfIn PDF document text
    • http://purofirstli.com/userfiles/files/rafemewagaj.pdfIn PDF document text
    • http://oroblupiscine.it/userfiles/files/wogusa.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148254f5f8ef---33810644988.pdfIn PDF document text
    • http://eyupsifalibitkiler.com/resimler/files/69044962714.pdfIn PDF document text
    • http://bilmatbasim.com/userfiles/file/12975920237.pdfIn PDF document text
    • http://hingliltd.com/userfiles/52464378538.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=friday+night+funkin+sky+apkPDF 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_off0000b533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB533 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd4a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD4A 10760 bytes
SHA-256: ed8827c9dd08dec128d254f997af6298572f7e4e84ffa3a8fcd35d0952cff9e7
font_02_sfnt_off0000e5b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5B9 16800 bytes
SHA-256: 706f77157fbdce1c32e26f160d95e66be4efd578d6cbd972074c3e06bcd52094