Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae3b8a5a391a3d69…

MALICIOUS

PDF

81.8 KB Created: 2021-10-11 03:30:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 74f7be4a20d8cfbad928d5a0e402fa94 SHA-1: 5970f09f4b74ba4915ddd00ac33e43953e88d300 SHA-256: ae3b8a5a391a3d69eaca37b17f690b7848949ac941d8ce0f90202f4400968cf8
156 Risk Score

Malware Insights

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

The PDF was flagged by multiple heuristics as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document body is heavily obfuscated and unreadable, but the presence of numerous external links suggests an attempt to redirect users to malicious sites for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://kargo-box.com/uploads/files/velipikuzubepelezewimuka.pdf In PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/d8e45e89a6db12a6a30b307c72bd1ba1/31520246153.pdfIn PDF document text
    • http://tonioloclaudio.it/userfiles/files/93067885024.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/nalak.pdfIn PDF document text
    • http://anm-av.de/uploads/files/79952705918.pdfIn PDF document text
    • https://padservhosting.com/userfiles/file/42602432464.pdfIn PDF document text
    • http://maslag.eu/userfiles/file/xizutoruvori.pdfIn PDF document text
    • https://gamepinleri.com/calisma2/files/uploads/fafaxugokubesutil.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/79363301092.pdfIn PDF document text
    • http://nhatnguyen.vn/media/ftp/file/81658455963.pdfIn PDF document text
    • https://lerivagedesmilleetangs.com/caningest/images/file/73183250525.pdfIn PDF document text
    • http://revize-elektro.info/UserFiles/File/sekirajarotogawenapi.pdfIn PDF document text
    • http://tandprotheses.com/ckfinder/userfiles/files/sixigamilatimiponi.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305157d00af---86042779092.pdfIn PDF document text
    • http://szermgrt.hu/uploads/ckfinder/userfiles/files/jizuwo.pdfIn PDF document text
    • http://geometracosentino.com/userfiles/files/80715530871.pdfIn PDF document text
    • http://goldstecq.com/userfiles/file/20178725313.pdfIn PDF document text
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131c92e5b98e---zoriripo.pdfIn PDF document text
    • https://suksesunited.com/contents/files/libevitasololujodadejati.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/ximagi.pdfIn PDF document text
    • http://vietkinggroup.com/uploads/userfiles/file/49935555999.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/bt43tt2ef39d8nf484mbv4c5hr/306911835.pdfIn PDF document text
    • http://balony.dmuchance.eu/userfiles/file/76622134850.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7a2b14b92---88981463345.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=martingale+forex+strategy+pdfPDF 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_off0000dc39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC39 17052 bytes
SHA-256: 05f00fd2a9a31c5a4442669d20fdf874651dc817c065bf61679533f29ef6eaa6
font_01_sfnt_off00010849.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10849 10884 bytes
SHA-256: 1fdef9ad214ecf4bc99fff7fc13a0ec7cfd77903051f6a9373cd82d6736976c2
font_02_sfnt_off00012169.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12169 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1