Malicious PDF — malware analysis report

Static analysis result for SHA-256 f298b069968637a5…

MALICIOUS

PDF

81.6 KB Created: 2021-09-16 17:17:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: eaf8ec4b04cdc0c33d38262220c71954 SHA-1: 38726633d3d72efc3729c20b21b8f1c456f4d38d SHA-256: f298b069968637a5b06618822681102227f88860f92014b6ef6aed5a8858537e
142 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URLs, including one pointing to 'synerhu.ru', suggests the PDF is designed to exploit vulnerabilities or redirect users to malicious sites. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the idea that this PDF is part of a larger malicious infrastructure, likely used for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://synerhu.ru/uplcv?utm_term=movie+maker+8+download PDF link annotation
    • https://www.ojchamber.com/ckfinder/userfiles/files/tifixuma.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/pejodaxob.pdfIn PDF document text
    • https://ichibaninfotech.com/ckfinder/userfiles/files/58760182562.pdfIn PDF document text
    • https://falconshipping-uae.com/userfiles/files/78428103330.pdfIn PDF document text
    • http://appartenvue.net/appart/upload/images/milemolasabikajopevapiv.pdfIn PDF document text
    • http://bangiyaparishadtoronto.ca/bpt/editor/uploadfiles/gufojutelaboleruje.pdfIn PDF document text
    • http://kaizousha.com/js/upload/files/75113707638.pdfIn PDF document text
    • http://mikomisushi.com/uploads/files/19037678178.pdfIn PDF document text
    • https://vresponse.net/userfiles/file/66423336187.pdfIn PDF document text
    • http://luberoff.com/userfiles/file/59661126859.pdfIn PDF document text
    • https://parquesanalbertohurtado.cl/ckfinder/userfiles/files/89291408140.pdfIn PDF document text
    • https://laptopserwis.com/app/webroot/media/files/93059102933.pdfIn PDF document text
    • https://resortweeks.pro/userfiles/file/topon.pdfIn PDF document text
    • https://yogaspotny.com/userfiles/file/1517003236.pdfIn PDF document text
    • http://hnc2.com/userfiles/file/nesuvomapeluvoweleb.pdfIn PDF document text
    • https://mimpidia2.com/contents/files/67622637439.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/52d4e85a5c4fb37c24246180ea7b4861/vevole.pdfIn PDF document text
    • https://duel.pl/userfiles/file/31679728491.pdfIn PDF document text
    • http://dangkykinhdoanhkiengiang.com/upload/ck/files/80111771862.pdfIn PDF document text
    • http://manuale.aziendasulweb.it/userfiles/files/wifolagovewosi.pdfIn PDF document text
    • http://amako-ra.com/wp-content/plugins/super-forms/uploads/php/files/0a8d80116bfa5c49d3dd92cfe6b6f17b/rugoneputifuwa.pdfIn PDF document text
    • http://nhactheducthammy.com/upload/files/papifaxag.pdfIn PDF document text
    • http://karcannakliyat.com/userfiles/file/52557984996.pdfIn PDF document text
    • http://synfarm.com/upload/files/32708185113.pdfIn PDF document text
    • http://dui-antidote.com/images/userfiles/file/3529926164.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_off0000dc1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f436.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF436 10588 bytes
SHA-256: dbc349d097c5f9b03d2e1c9391f14ca0815fd0ab5b2dd10e398b96b95085e1df
font_02_sfnt_off00010c60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C60 17172 bytes
SHA-256: 1e4963adca07e22a0a7952c41d670c73d0c2d1692db63e95c3b37b42222274dc