Malicious PDF — malware analysis report

Static analysis result for SHA-256 a76b200af8de879f…

MALICIOUS

PDF

96.2 KB Created: 2021-09-14 13:02:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 42c9f2bd6202548f3274e2f190db494e SHA-1: 8958e4ebf248102b4906d6b019479d9c6e60a28c SHA-256: a76b200af8de879f605e790a1cac54c05135d2b2cf90d0c5208da5c8b3b39c89
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. Heuristics indicate it functions as a link farm and contains a callback lure, suggesting a phishing or tech-support scam. The document body is heavily obfuscated, preventing analysis of its specific content, but the presence of numerous external links and the callback lure heuristic strongly indicate a malicious intent to deceive the user.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://samsungklima.net/upload/ckfinder/files/42542941429.pdf In PDF document text
    • https://altsovmun.ru/userfiles/file/nubugobek.pdfIn PDF document text
    • http://administratieindex.nl/images/uploads/70626357977.pdfIn PDF document text
    • http://geasit.it/userfiles/files/jewirududoduvomewapelavi.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/zidoximudibatixuma.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613ef4c0344da---80952811806.pdfIn PDF document text
    • http://www.ferm-matic.fr/upload/file/dugug.pdfIn PDF document text
    • https://comfortinnbarrie.com/phpsites/vertical_living/uploads/file/zipavasumakelejusogovu.pdfIn PDF document text
    • http://tpt.taipei/asset/uploads/files/94732554233.pdfIn PDF document text
    • https://reklama71.ru/upload_picture/wakalelu.pdfIn PDF document text
    • http://01host.ru/userfiles/files/tomidafudunijuxujukufo.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/69979424429.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/vovunapemibegeriladivib.pdfIn PDF document text
    • http://privateeducation.sg/verzsape/demo/upload/admin/files/10550532630.pdfIn PDF document text
    • http://kingsfinancialconsulting.com/userfiles/file/mumulazuxoxolowul.pdfIn PDF document text
    • https://altsovmun.ru/userfiles/file/59879776394.pdfIn PDF document text
    • https://coop-alternatives.fr/images/images/632845303.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1630742261.pdfIn PDF document text
    • http://brunagabriele.it/userfiles/files/88003232842.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/fanudo.pdfIn PDF document text
    • https://codecs.ro/images/file/65633013124.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/10709258023.pdfIn PDF document text
    • http://24horasnoar.com.br/ckfinder/userfiles/files/zeguxaxaratezamuzejoxakox.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/dujomazen.pdfIn PDF document text
    • http://hadt.vn/upload/files/wajugofoxewuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=maps+for+android+wearPDF link annotation
    • 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_off000113ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x113AB 10428 bytes
SHA-256: 29e3d65ed0a5a0fd0fb48d41a58ce8c7651dcbcf2c93f68e86ff5302b423bcd8
font_01_sfnt_off00012b80.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B80 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014392.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14392 18312 bytes
SHA-256: 917f686094b0f6f150c7ace3907cb7190bd9b6f3e5a41a1acb5ea5bb9ef0a566