Malicious PDF — malware analysis report

Static analysis result for SHA-256 818107dbc8a6c6d6…

MALICIOUS

PDF

105.8 KB Created: 2021-07-29 18:13:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e51b69159ce9496c4a719e884e182479 SHA-1: 61d49c3ea06510b39ad23db42953fcdcdd3a44ec SHA-256: 818107dbc8a6c6d6c7fd0acf570297d58656ed3dff34db62754807defc7d500f
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9969

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
  • 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://bjhtdszdh.com/v15/Upload/file/2021510159155344.pdf
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/u0g3jhj28abfgja6rngu97sgc1/80669640291.pdf
    • http://candientu24h.vn/webroot/img/files/62873188072.pdf
    • https://carea2plus.com/wp-content/plugins/super-forms/uploads/php/files/66b4dbdbe6c74debddcd729fa4fe4db9/situbu.pdf
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160876e329a8dc---gofadefavegikemedagafezin.pdf
    • http://baaningdoi.com/file_media/file_image/file/perapo.pdf
    • https://gadd-asso.org/userfiles/file/bolujeb.pdf
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/b5ehv8gvai8a7sainj1hb3pso9/47506939705.pdf
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/a666831e8637de33a3f5b6d05b0193ef/fusebolorizegunezisi.pdf
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cabf7cde648---ziboduforimun.pdf
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/386817256730828320d73c23c1c3bcff/79501879272.pdf
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/egvq27cth2ko3gmhpgp4pmjjbg/84275022763.pdf
    • http://dermalab.pl/userfiles/file/39423058548.pdf
    • http://on-video.com/movies/movie_data/file/18754422283.pdf
    • http://giadinhlaurenso.org/upload/files/fefoxunekakufukulupabud.pdf
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/3b118baf5f49be6040f14fd7b9f1fc6c/pagopizotalemo.pdf
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/mbdbqokd6iskfasge3n2ebl6h7/velozataxafemewukej.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ad5d453c9a---dunusizutokekivusozegap.pdf
    • http://rauvuonsach.com/images/uploads/files/botom.pdf
    • http://ascensionchina.com/userfiles/file/bekirigir.pdf
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16073286a3de72---welaparix.pdf
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607166bbb8de9---mivubimedaridofibasunux.pdf
    • https://smartstone.ca/userfiles/files/48124492393.pdf
    • http://korean-school.hu/hangul/userfiles/file/jakowoxojivobinob.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=how+to+say+lease+agreement+in+spanish
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001380c.bin
625a6226ac96a306a121a65077cb56d29874aefd1a5dc2999d365e3316db2284
pdf-font-stream PDF embedded font (sfnt) at offset 0x1380C 10892 bytes
font_01_sfnt_off00015117.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15117 16792 bytes
font_02_sfnt_off00016929.bin
7759e5b1b6483720ad282258cdf4a676159b793bfa751ca89e5792895a28880c
pdf-font-stream PDF embedded font (sfnt) at offset 0x16929 17848 bytes