Malicious PDF — malware analysis report

Static analysis result for SHA-256 99760519d73b233b…

MALICIOUS

PDF

82.3 KB Created: 2021-08-30 11:52:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 6078fbb8c86f88d3b22523dbf07a9b02 SHA-1: ff7cdec3c8a360178bdc19f40397783b581d686c SHA-256: 99760519d73b233be4e95edf0ff2cd5b5dedd978732055d0f686b14d10105fbe
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and a machine learning classifier. It functions as a link farm, containing numerous URLs that point to compromised WordPress sites and other domains. The presence of these links suggests an attempt to redirect users to malicious content, likely for phishing or to download further malware. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://krisoc.ru/uplcv?utm_term=how+to+remove+black+circle+security+tag PDF link annotation
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078cd4e4c672---6129220786.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/5dq1i008j7fn585vdiueqs8htm/zibokedit.pdfIn PDF document text
    • http://hoaisonland.vn/upload/files/82013949728.pdfIn PDF document text
    • https://nikosdimos.gr/userfiles/file/34456458727.pdfIn PDF document text
    • https://fibra-optica.ro/ckfinder/userfiles/files/94718165532.pdfIn PDF document text
    • https://fullhousetourism.com/UploadFiles/file/20210621114839152.pdfIn PDF document text
    • http://artospace.com/pics/file/68993541565.pdfIn PDF document text
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609b21032c75b---kosuw.pdfIn PDF document text
    • https://vvpta-irvine.org/userfiles/file/86075642541.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/99118485573.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/v0tkk4mahach7id3ulqebrie0i/1481888385.pdfIn PDF document text
    • http://superlitefan.com/uploads/files/27806341421.pdfIn PDF document text
    • http://insureacompany.com/userfiles/file/jutasegoduraguvotipafu.pdfIn PDF document text
    • http://snkpost.com/fckedit_file/file///20210816_3_29_20.pdfIn PDF document text
    • http://jpmoto.biz/upload_picture/wepodopunipegirozoguzixif.pdfIn PDF document text
    • http://onlinepravenconsultant.com/uploads/wysiwyg/files/rovareg.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/59d4d6ac7f20dc77e6f83c46a8e24ece/linefejidi.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/90795564354.pdfIn PDF document text
    • http://tehpromyar.ru/media/file/64664791881.pdfIn PDF document text
    • http://protok.pro/upload/files/sexil.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/161207efda89f0---21776061614.pdfIn 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://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_off0000d60b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD60B 19708 bytes
SHA-256: 3e067b4be9140f326292b5f6ed20f58242b4e3a3248b18345bc264a66ce58ba9
font_01_sfnt_off00010990.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10990 11060 bytes
SHA-256: aa256a75bec8f3fefb1221c952e80e5fbe157d6a8d620e0d8bf7f55073b65d15
font_02_sfnt_off0001236e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1236E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1