Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b30c553c81f90f9…

MALICIOUS

PDF

87.7 KB Created: 2021-06-29 23:54:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 93b3dbac1a720ade5cf8766ac4d9cc5a SHA-1: f90e33e461002e02573df9c225f49cb3b00c2c86 SHA-256: 5b30c553c81f90f9020e9899ab21aae777c2404cc7f183c0077c925d341dd5d1
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting it's part of a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://alexlunacoach.com/img/editor/file/5657581820.pdf
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/30d7c7ef43e4307a6cae56b96b9176a3/35428559470.pdf
    • https://cor.org.ar/wp-content/plugins/super-forms/uploads/php/files/5nr97l6hrui00sunp0nbt57ijh/piwulafa.pdf
    • https://paklya.su/design/img/upload/file/naxopefiwovilifema.pdf
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/bhjk6hp196dr68da8a6p3h3t3i/41227289637.pdf
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/c0cg1uffh47j87a5nqce4hfor7/40318937612.pdf
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/biafjatbsjhev9ifoa9787gu90/nisivila.pdf
    • http://laiyi-art.com/userfiles/file/rebelexuxika.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8f81e98987---nufajexikemavidixajem.pdf
    • https://pensiuneavalentina.ro/app/webroot/file/turepagazuga.pdf
    • http://automsystem.com/UploadFile/file/20210612111121485.pdf
    • http://cosmickino.ru/sadm_files/rimoregomunutozo.pdf
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/b9600249bc940c3b00372cf9a1e7295d/71770028153.pdf
    • https://noihoithanhtuan.com/media/ftp/file/87893999860.pdf
    • https://www.nrlandscapes.co.uk/wp-content/plugins/super-forms/uploads/php/files/abced4d41eec39f5f6010ee6795975ab/16869775901.pdf
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a8905b77222---waverojulenu.pdf
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/l8kkm7g45dup6achv2e10etd0u/jumudew.pdf
    • https://dancleland.com/img/upload/file/rofurovisadez.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609c116bd33c9---zagifekigib.pdf
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/276ac68e56935514ebea36f6919e5f01/78784238827.pdf
    • https://autoandtruckrepair.net/nbloom/fckuploads/file/zujuzo.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c62c5b26650---tipafipakubiwenale.pdf
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/7dceeceb6cbf30c3eb5434d845b60f60/88450151509.pdf
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16072acd6224b4---zaboxovivi.pdf
    • http://mg001.cn/upload_fck/file/2021-6-19/20210619193114660453.pdf
    • http://matstravel.ru/userfiles/file/donusukevajujewo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=differential+equations+pdf+books
    • 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_off0000f0b2.bin
066ce8979414eb457109ae5c8ca8f4ad284c8da0eb425e608be243c32daed223
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0B2 18304 bytes
font_01_sfnt_off00011ff8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF8 16792 bytes
font_02_sfnt_off0001380f.bin
ea289e8b576b78216b8765da8001556b6b9e4fcb50193e171dcca796162ae380
pdf-font-stream PDF embedded font (sfnt) at offset 0x1380F 10968 bytes