Malicious PDF — malware analysis report

Static analysis result for SHA-256 8681ff0fe82b2588…

MALICIOUS

PDF

81.6 KB Created: 2021-09-04 14:50:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 656040a897c013de743beeb61b02c49d SHA-1: 485876d33146089b70ca09d508d2519755a5e73e SHA-256: 8681ff0fe82b25885039c5b7e5a4d6f78d6ab1ebe6076b89576959ec659d9de8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a link farm hosted on multiple compromised websites, suggesting an attempt to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, with ClamAV identifying it as Pdf.Phishing.Trojan. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607c16f4bafa6---torejelavobemaloj.pdf In PDF document text
    • https://aimhc.com/userfiles/file/16492401080.pdfIn PDF document text
    • http://akekaluck.com/ckfinder/userfiles/files/29805692548.pdfIn PDF document text
    • http://johndanton.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/16783817838.pdfIn PDF document text
    • http://tasteofruraleurope.eu/upload/File/jofolejovatibireso.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1611168b0e7278---4120555739.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/3ac2d7eea3a80a3e670951ee9faebef6/95691471764.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/sngh31k125b1lf0hdafrf7s635/tedoterakasezija.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/53d4787662ca9fbc6bbc4382151f822f/49492550599.pdfIn PDF document text
    • https://kaptenhoki.com/contents/files/kejobedibalin.pdfIn PDF document text
    • http://mariekevanvlierden.nl/survey/userfiles/files/mibajupoguduvapabanebo.pdfIn PDF document text
    • https://elpmarketing.ca/wp-content/plugins/super-forms/uploads/php/files/15a0a376c792cbc369d17f8d1dc8a7ce/jobanamuwojirosodixuvuku.pdfIn PDF document text
    • http://thinhhoanggia.vn/Images_upload/files/80615393569.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/10009597736.pdfIn PDF document text
    • http://www.texaco.bargiel.com.pl/ckfinder/userfiles/files/mupamafegededazejisugu.pdfIn PDF document text
    • http://eurekaelearning.com/upload/news/file/wuveliberupati.pdfIn PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/motidegawapexaliwutesax.pdfIn PDF document text
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f1091d0ca2---bifire.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/88170793374.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608416a882da5---93498654313.pdfIn PDF document text
    • http://biotop-zamosc.pl/userfiles/file/pevojujiwiwan.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607592ddd1858---xegexebuxifemugoradaduli.pdfIn PDF document text
    • https://sp-pir.ru/wp-content/plugins/super-forms/uploads/php/files/e4f75121ed7cfbfbf92a06bfc5983458/vigaremifam.pdfIn PDF document text
    • https://estoniapools.com/contents//files/musokizowapisobe.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a31ec111f5b---vademegibezixefana.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=raindrops+keep+falling+on+my+head+piano+sheet+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d73b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF52 11196 bytes
SHA-256: e55da06ced8394041d59222f71a317d24f36aa9025aaddd880e464f0cce9d9d4
font_02_sfnt_off00010922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10922 17820 bytes
SHA-256: 31730f2d8cd5c366622fe1be11a05a13b1e443e354b8236c726537e7b6a773c7