Malicious PDF — malware analysis report

Static analysis result for SHA-256 917c59371c3792ee…

MALICIOUS

PDF

79.8 KB Created: 2021-09-18 20:08:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1e8b52d76cab924aeb2e2e4b46664218 SHA-1: 7d01431d73f04399a0dec23b4ed8c24022f8712f SHA-256: 917c59371c3792ee2739cf4dd1179c64611c62ee31bd64751f6f7ffa30ec51f9
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by multiple heuristics, including a critical ClamAV detection and an ML classifier flagging it as a phishing trojan. The presence of numerous external URLs, many pointing to PDF files on disposable hosting, suggests a link farm designed to obscure the true malicious destination. The 'SE_CALLBACK_LURE' heuristic specifically indicates a callback phishing or tech-support scam pattern, where the user is prompted to call a number for a fake issue.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://laborke.ru/uplcv?utm_term=find+deleted+emails+on+iphone PDF link annotation
    • http://enricobarraco.com/files/352834198.pdfIn PDF document text
    • http://www.moyekolodin.com/files/58513374433.pdfIn PDF document text
    • https://bank-kredit.at/ckfinder/userfiles/files/lamuv.pdfIn PDF document text
    • https://www.nhabe.com.vn/ckfinder/userfiles/files/kagagomagofuv.pdfIn PDF document text
    • http://chroscina.com/userfiles/file/78642280736.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/gepopukasulup.pdfIn PDF document text
    • http://elcampoeco.org/FCKeditor/file/94177456466.pdfIn PDF document text
    • https://mimpiindah88.com/contents/files/suvajagowopeguwisepo.pdfIn PDF document text
    • https://tutorbolivia.com/userfiles/file/borilalefoso.pdfIn PDF document text
    • http://bannhuaduong.net/upload/files/rubiri.pdfIn PDF document text
    • http://tuderprogettazione.it/userfiles/files/31953598904.pdfIn PDF document text
    • https://mahanakhon.pacedev.com/ckupload/files/kilawenixiruxiteker.pdfIn PDF document text
    • http://sdhmladavozice.cz/userfiles/file/temuwegogixeloze.pdfIn PDF document text
    • http://www.iuoelocal870.com/kaizen/ckfinder/userfiles/files/63866885305.pdfIn PDF document text
    • https://www.q-jin.ne.jp/ckfinder/userfiles/files/wurigixukojevorofumerelav.pdfIn PDF document text
    • http://thuonghieutoancau.vn/uploads/files/wowudigaxunuguwumabunik.pdfIn PDF document text
    • https://terracell.pt/images/file/pelawunitisoluperuwude.pdfIn PDF document text
    • http://ogcdc.org/uploads/ck_upload/files/kajafigo.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614579e1b0faa---90839338696.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210904072557.pdfIn PDF document text
    • http://massvt.sk/editor_uploads/system/files/49027151210.pdfIn PDF document text
    • http://marcelponjee.nl/ponjeefiles/file/45518204491.pdfIn PDF document text
    • http://somkuthyoptika.hu/editor_up/fetibezoxovofakafiperi.pdfIn PDF document text
    • http://e5tbr.alruaa.com/ckeditor-ckfinder-integration/uploads/files/17177468910.pdfIn PDF document text
    • http://www.elstar.ru/uploads/files/bojigatarevuriliwapofebuv.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_off0000d3b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3B1 17880 bytes
SHA-256: 1da7001a82eb6d49f08b1a997aeaebb2e2a48101234ef83e1749a02278eaef85
font_01_sfnt_off00010203.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10203 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A1A 10532 bytes
SHA-256: 50fbb5296e201386594e58599e0ea79f543ca7450b9d97a07c5d804254e08d48