Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d8c9e610c41b651…

MALICIOUS

PDF

75.3 KB Created: 2021-09-21 18:35:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8818ddf7dba65f583d09b73ad0c497c8 SHA-1: bc776c7b78d860dc390567cfb3697928921643f7 SHA-256: 5d8c9e610c41b651496d35cd79d0f1dbaadbe55946ddb0c2d58bc9e2fc1dea4f
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous embedded URLs pointing to disposable domains and a link farm pattern suggests an attempt to direct users to malicious websites. The 'SE_CALLBACK_LURE' heuristic further indicates a potential phishing or tech-support scam pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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
  • 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://cructi.ru/uplcv?utm_term=gauge+theory+of+elementary+particle+physics PDF link annotation
    • http://househouse.it/userfiles/files/7562283042.pdfIn PDF document text
    • http://kzlo.pl/fotki/fotki/file/nudomakepufudebima.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134177737278---lifaworeredipamar.pdfIn PDF document text
    • http://xaydungphongphu.com/uploads/files/zenukelezof.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/zadil.pdfIn PDF document text
    • http://lidaoxc.com/upload/files/51323576841.pdfIn PDF document text
    • https://zoorichi.com/temp/fckeditor/file/gurewedajiro.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/pobew.pdfIn PDF document text
    • http://www.gabrielamaciel.net/images/content/file/kolajiz.pdfIn PDF document text
    • https://avflash.nl/upload/files/pinakaputukasek.pdfIn PDF document text
    • https://willes-gb.com/uploads/files/202109122202014510.pdfIn PDF document text
    • https://777mto.org/contents/files/83344746215.pdfIn PDF document text
    • http://newtarrytowndeli.com/uploads/files/pijikujexixedu.pdfIn PDF document text
    • https://tavfelugyelet.megujuloenergiapark.hu/admin/ckfinder/userfiles/files/vosifizotedol.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134e73e45616---63430071884.pdfIn PDF document text
    • http://hanasushi6.com/uploads/files/7651475393.pdfIn PDF document text
    • http://abw10thstreetne.com/uploads/files/tawogubifatuge.pdfIn PDF document text
    • https://mingyi-lock.com/data/file/userfiles/files/4677545781.pdfIn PDF document text
    • http://sarkar.ie/userfiles/file/kemuzuxadasa.pdfIn PDF document text
    • http://vhshf.de/File/36269310797.pdfIn PDF document text
    • http://totoumi.jp/upload/file/wopunirazuxesijoba.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_off0000bd27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD27 17868 bytes
SHA-256: 1d2098c4faf23e984540e4969afae94c4f6de7a2f572f25300c22e8d24fc9092
font_01_sfnt_off0000ebe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBE4 11180 bytes
SHA-256: b0a8dc546c5bdeed12023c6a7255620f516e09fd7d967fb6671b59665183217e
font_02_sfnt_off000105eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1