Malicious PDF — malware analysis report

Static analysis result for SHA-256 8755c8236930c04a…

MALICIOUS

PDF

88.0 KB Created: 2021-07-31 10:48:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a5bfae3e68afc787190192417e0eec91 SHA-1: 1e369073420640697b6499f577b1767ef7bda15f SHA-256: 8755c8236930c04a716a98fbb924bf4a3af30f7312f2baac62f96387177da57c
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs pointing to compromised websites and link farms, suggesting a phishing or malware distribution scheme. The presence of these links indicates an attempt to redirect the user to malicious content, likely exploiting a PDF vulnerability or social engineering.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://archism.ru/uplcv?utm_term=ejercicios+de+suma+resta+y+multiplicacion+para+cuarto+grado
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/9qtdc2ln1stfoc74pjkvbhekqj/sopodifetufiwokodenum.pdf
    • http://rauvuonsach.net/images/uploads/files/86017985205.pdf
    • http://dioceseofniranam.org/userfiles/file/31514186411.pdf
    • https://stauber.lt/images/files/xitusuguwozowegope.pdf
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6d5091544f---60314397376.pdf
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f6dc266079---77534234471.pdf
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/377e9616beb085b3dcee70179443e30d/zitagepegoziwekevepixori.pdf
    • http://ud2-140.com/files/fotusebo.pdf
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/94a7655d1ae834c43d69779ff767e832/36822162736.pdf
    • https://samsungklimalar.com/upload/ckfinder/files/puxadevitibanutimajerulaz.pdf
    • http://safires.cz/ckfinder/userfiles/files/40764151326.pdf
    • http://mtreurope.com/ckfinder/userfiles/files/86752888742.pdf
    • http://aite-materials.com/upfiles/file/podatile.pdf
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/5010739085.pdf
    • http://jandebruijn.com/uploadimages/files/tapumejowubel.pdf
    • http://abpaluso.com/upload/file/62619495917.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087b8c37a4e2---39794666773.pdf
    • http://lamekatus.ee/uploads/ckeditor/files/bugudonabevefavupanipon.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/8264lfq1tjoennr95na4ckd6uq/lawiwibanibomoxikon.pdf
    • http://phanphoiongnhuahoasen.vn/upload/files/lujenalebosovuk.pdf
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b57eac92bdc---xoxedu.pdf
    • http://sun-green.de/ckfinder/userfiles/files/jigujukovemofodorajite.pdf
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/fdee8a289f7ec4bce5c93d6758a4a380/98420889729.pdf
    • 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_off0000ee95.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE95 16792 bytes
font_01_sfnt_off000106ac.bin
8d779f11926d516a8c06a86eed4d566286aa7a5c377f7f95ff9bbbba8ebc85a8
pdf-font-stream PDF embedded font (sfnt) at offset 0x106AC 11184 bytes
font_02_sfnt_off0001209b.bin
22d4927a9c7e1fa59787d04aaa16813d9df8337a68564ed869fe8c8fac65cd33
pdf-font-stream PDF embedded font (sfnt) at offset 0x1209B 19156 bytes