Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a7aa603fd8adde8…

MALICIOUS

PDF

87.8 KB Created: 2021-08-09 09:18:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4a6b6cb751dc48617690d0affdc2d50 SHA-1: 048a9f25a15ca0b6332654e9f5422d6feb0ca128 SHA-256: 8a7aa603fd8adde810f6bc7baa82f94819e6809b906e40db8b047b9def43947b
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable hosting. The embedded URLs and the nature of the heuristics strongly suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://photo-preiss.com/upload_files/files/wedurerurowafokod.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160c4eb7e568b1---kogisexazirazam.pdf
    • http://kanstm.com/ckupload/files/8809064375.pdf
    • http://matstravel.ru/userfiles/file/meligedu.pdf
    • https://ilc.ua/wp-content/plugins/super-forms/uploads/php/files/k7thba45a53ts7ej4a6lsk6754/sotepiwomugifebabukumeka.pdf
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202105061349122710.pdf
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160d32cdf0c08b---73571057816.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/e8579c309661271cf6456ccdbf71531e/nixofusu.pdf
    • http://doubletroubels.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d01f318c19---6771852702.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c7625cc31---bumokarom.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/41b57da423d5f1d569791ddd01244c63/68232242945.pdf
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/01c2172cfb1cb20f2a2437cb59cb8a72/64391236498.pdf
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/627a4c47c4ef59636ffa3ad34760d1d5/75655759826.pdf
    • http://efeotokiralama.com/Upload/file/21046197920.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160e6ba8c670f0---10739421252.pdf
    • https://cobrawire.com/userfiles/files/42851569259.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b08e4f45c---duterisegufoma.pdf
    • http://elfuklid.cz/foto/Image/file/fireremud.pdf
    • https://talleresimad.com/images/subidas/files/47151573778.pdf
    • http://suachuaspa.com/upload/images-content/files/walovadu.pdf
    • http://belst.by/upload/file/pikokajivizuz.pdf
    • https://www.kasekimi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084c1d7189d0---tidevopezis.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=why+is+my+dog+hiding+from+me+and+shaking
    • http://s292376414.onlinehome.fr/datas/imgmail/file/saxadukowew.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_off0000f4fd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF4FD 16792 bytes
font_01_sfnt_off00010d14.bin
46a32141c2ec994f189bf9b8966faffb4bcd650625894a20a231a74c2146929e
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D14 10856 bytes
font_02_sfnt_off000125bc.bin
090b4661a803ca212d210e8b4a567cb3078fd5c3e0aa5fc64f557b3e3d5d1d21
pdf-font-stream PDF embedded font (sfnt) at offset 0x125BC 16304 bytes