Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d9c813955e4e886…

MALICIOUS

PDF

84.1 KB Created: 2021-09-21 17:14:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: dcfcdd1744f00deca2dcba26ac34dba7 SHA-1: 91cd8d88ea05ee3e7a52716109b3ea494ca28ff1 SHA-256: 8d9c813955e4e88631d9c4fadfce23a8b29063ce354e7c6e8169ce90b59133c0
166 Risk Score

Malware Insights

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

The PDF document was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm and employs a social-engineering lure to trick users into installing browser extensions or updates. While no scripts were directly extracted, the nature of the lure and the detection signatures suggest potential for JavaScript execution or exploitation to download and execute further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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://craftland.de/res/wysiwyg/file/16982283509.pdf In PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/16130c989dc33a---jekojelaf.pdfIn PDF document text
    • http://baocaosuhoatoc.com/luutru/files/jiwazurojirikipo.pdfIn PDF document text
    • http://eng.sut.ac.th/tce/2016/administrator/ckfinder/userfiles/files/fabus.pdfIn PDF document text
    • http://agataklimowska.pl/userfiles/file/vunirinozufagufesowojugow.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16130af75a4846---68158500963.pdfIn PDF document text
    • https://tierrettung-in-katalonien.org/ckfinder/userfiles/files/60242284065.pdfIn PDF document text
    • https://ijieet.org/ckfinder/userfiles/files/95579926831.pdfIn PDF document text
    • https://pepinieramontana.ro/ckfinder/userfiles/files/21500616507.pdfIn PDF document text
    • http://www.520amis.com/upload/files/52158679906.pdfIn PDF document text
    • http://wsm.hk/images/uploadfiles/file/52574327306.pdfIn PDF document text
    • https://conexusinternational.com/ckfinder/userfiles/file/3405375078.pdfIn PDF document text
    • http://xn--sanitrprofi-p8a.ch/fckeditor/editor/images/file/97597373427.pdfIn PDF document text
    • https://architektor.ru/uploads/file/45822794296.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/sulasujinewuzezud.pdfIn PDF document text
    • https://krusomying.com/data/file/45614182356.pdfIn PDF document text
    • http://mikol-styl.cz/userfiles/file/42603490183.pdfIn PDF document text
    • http://www.me.ntou.edu.tw/ckfinder/userfiles/files/20210913_220233.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/basimimixefojukimuwobu.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/bodunavexexaxov.pdfIn PDF document text
    • http://yibetter.com/data/files/pavusefizofeveliwo.pdfIn PDF document text
    • http://www.rupankar.com/fckimages/file/48495316969.pdfIn PDF document text
    • https://reparation-mobile.net/userfiles/file/sulodoravasobafowaba.pdfIn PDF document text
    • http://shlawllc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/27842654383.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=advanced+c+programming+by+example+pdf+free+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_off0000e101.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE101 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF918 11184 bytes
SHA-256: 6ef89a8340b716c414eec67ab8c49ed6afbd0e9a9ff66118a61ab473c3835933
font_02_sfnt_off000112db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112DB 18332 bytes
SHA-256: 2b90e14eb80e756ab05d346f45affb6059e11b32d75e16d925ef8ff0b05c3eba