Malicious PDF — malware analysis report

Static analysis result for SHA-256 751b2b6e92129e61…

MALICIOUS

PDF

76.2 KB Created: 2021-06-07 23:06:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: d2ec0e6973b25bbf43694d562e648ff3 SHA-1: db670d753f21306b6d656e73a0606627c0886cf7 SHA-256: 751b2b6e92129e61b4338fb15a3207dfe1f93f9c0fe41fb877fdb141caae410e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm or phishing campaign. The heuristic 'ML_NYX_PDF_MALICIOUS' and ClamAV detection confirm the malicious nature of the file. The document body, though heavily obfuscated, contains text related to 'hku admission score 2018', indicating a lure to attract victims interested in academic admissions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://catamma.ru/uplcv?utm_term=hku+admission+score+2018 PDF link annotation
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/2tbkbjvoci3o6kkoe85l1im9tk/24744169643.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/pobagovatigexabopenopowo.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/p65tvk1p0jaoh4d95k2pqo6q2i/49956394386.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608a30251033b---47963274636.pdfIn PDF document text
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/adb442a390874f014ce02fa7849d696e/98121370114.pdfIn PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/1efc26baf6a3bd715b6bab739433d098/23291066031.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/xurinaba.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/2163738052.pdfIn PDF document text
    • http://nnk.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b0a577c60a1---katiligudupatigukegisum.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd152ecf7e---xubazela.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd4c362a26c---kofeguveder.pdfIn PDF document text
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160949c7dbed07---64367919090.pdfIn PDF document text
    • http://amphorabeautyclub.com/campannas/file/73213066460.pdfIn PDF document text
    • http://stalmost.pl/userfiles/file/vomoma.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608919ce106e7---93382679583.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16075f62bed465---fonilosuzesokipamur.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/xuzimozibose.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d62b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD62B 5708 bytes
SHA-256: ad917a829d15be07127406323063124ba0c5c1abef4594a2d78a1ebc97f9513e
font_01_sfnt_off0000e991.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE991 5596 bytes
SHA-256: 40828750b9dcd136dda8e69c5aeaee2979fe4bf0ca1d81982003f369f0152212
font_02_sfnt_off0000fc83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC83 11024 bytes
SHA-256: f35d8c7330f92f4b1a9d6a9b6ccce3236a955b6baba4f39e83b115b847b9ed28