Malicious PDF — malware analysis report

Static analysis result for SHA-256 acac26e28fdc4dff…

MALICIOUS

PDF

83.6 KB Created: 2021-08-19 05:54:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 826d86790a0f91cd9927a82567041ba9 SHA-1: 7bbaf4dc7983df70046ffe617ee09100641e59c0 SHA-256: acac26e28fdc4dff80b124107834bf60defbfd11398e373cc55a7fff13839e4f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many pointing to compromised WordPress sites, suggesting a link farm or redirection scheme. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://www.adler-leitishofen.de/wp-content/plugins/formcraft/file-upload/server/content/files/16106ceb96bfdb---rajolamuxukizakado.pdf
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/52778229302.pdf
    • https://www.alitec.es/js/ckfinder/userfiles/files/vibojotaka.pdf
    • http://docando.es/js/ckfinder/userfiles/files/20982485210.pdf
    • http://kaizousha.com/js/upload/files/3583399830.pdf
    • https://hifi-markt.eu/kunden/kronhardt/ckfinder/userfiles/files/33824086288.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608978961af74---zuxemi.pdf
    • https://ryokanclub.com/FileData/ckfinder/files/20210725_AF1413D55998250F.pdf
    • http://constructionone.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609be119682f5---kalit.pdf
    • https://sport-jicin.cz/dokumenty/51993820718.pdf
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ba781819040---69390392608.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/16077ebac5a2a9---lavozigo.pdf
    • https://wacee.net/wp-content/plugins/formcraft/file-upload/server/content/files/16075aa3a61ddb---1500974236.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/1608aa84ac7abd---5720917163.pdf
    • http://lex-ter.ru/admin/ckfinder/userfiles/files/23365278549.pdf
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/3dd0f30ef8d9cbb3cd7482eb0b934e42/74240306626.pdf
    • http://gartenstadt-apotheke.com/userfiles/file/64195249667.pdf
    • http://ngpsusa.com/wp-content/plugins/super-forms/uploads/php/files/ecea3k92hc4j5mv13nipaodhqa/buzazodigutaputunab.pdf
    • http://xiangzhuan.tw/upload/files/83326516163.pdf
    • http://achilleferolla.it/userfiles/files/lebubunamovawak.pdf
    • http://indyskischool.com/ckfinder/userfiles/files/80306038436.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d22bbf8f794---magovurujurepel.pdf
    • https://hoakhanh.vn/uploads/image/files/86264524242.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/7999c772ada726f32c0d007d811df8ea/nazaxapalovawibamiwag.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=un+metro+cubico+de+piedra+picada+cuantas+carretillas+son
    • 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_off0000df0a.bin
9e9e9d3a2378d9660711423879db16b5b9a0e57c73c6386e3ebbb5e1b76dd127
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0A 10924 bytes
font_01_sfnt_off0000f80c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF80C 16792 bytes
font_02_sfnt_off0001101e.bin
57806389f1a5b25ead549f143953905103209c7be7e309106d5af6325fd435c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x1101E 18556 bytes