Malicious PDF — malware analysis report

Static analysis result for SHA-256 19db40f6a7cb75c9…

MALICIOUS

PDF

85.0 KB Created: 2021-02-21 23:32:40 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: d37c8c5ea08a7318695679570e2af3cb SHA-1: b13cfb17c9acb029e2fe3a678de72a7dc2ff6a48 SHA-256: 19db40f6a7cb75c9110d7de53323480cb7eb38e7ceb415ef757d42933b25cd47
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, with a critical heuristic identifying a link farm designed to boost SEO. The document body, though heavily obfuscated, suggests a lure related to academic worksheets. The presence of embedded URLs and the ML classifier's high confidence score indicate malicious intent, likely to redirect users to malicious sites for further exploitation or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jacksth.ru/wix?keyword=worksheet+4.3+law+of+conservation+of+momentum+answers PDF link annotation
    • https://tavugalijob.weebly.com/uploads/1/3/1/1/131164394/f9783940950.pdfIn PDF document text
    • https://tepikibinaf.weebly.com/uploads/1/3/2/3/132303010/mubunutedim.pdfIn PDF document text
    • https://cdn.sqhk.co/fedovusig/k0iahel/dreamlines_gmbh_wikipedia.pdfIn PDF document text
    • https://cdn.sqhk.co/narulaloro/i1Xhdwv/gaziva.pdfIn PDF document text
    • https://jogijomovap.weebly.com/uploads/1/3/0/9/130969693/famosove_matusewab_supaxuxupikup.pdfIn PDF document text
    • https://cdn.sqhk.co/wimiwupo/AigrjhS/fizejufofaduvatamamajiv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/jazofi/tuwukikukofixudeka.pdfIn PDF document text
    • http://tawatibajat.rf.gd/42847331353.pdfIn PDF document text
    • http://garaben.rf.gd/wordly_wise_3000_book_5_lesson_13e_answer_key.pdfIn PDF document text
    • https://s3.amazonaws.com/norozovijalu/code_formatter_in_notepad.pdfIn PDF document text
    • https://s3.amazonaws.com/ditiruz/26047707010.pdfIn PDF document text
    • https://s3.amazonaws.com/norozovijalu/brilliant_lighting_19479_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/vukujidor/command_prompt_cheat_sheet_windows_7.pdfIn PDF document text
    • http://danijikuguwidak.rf.gd/km_to_metres_worksheet.pdfIn PDF document text
    • https://s3.amazonaws.com/fejakixoweka/99432024810.pdfIn PDF document text
    • https://s3.amazonaws.com/lebaxa/95869476519.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ec4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EC4 5636 bytes
SHA-256: a51949eea34764a7256ef00e25a1428327bd8318666d9e186fb35050af963a4e
font_01_sfnt_off000121ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121EF 10696 bytes
SHA-256: e4c243a330854f57643ecc5dc315112fe125356e9e410b8b61472a1518adb2bc

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