Malicious PDF — malware analysis report

Static analysis result for SHA-256 25e4923948b9d803…

MALICIOUS

PDF

77.9 KB Created: 2021-09-22 11:07:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1da25339a046206de579bc563acba4b5 SHA-1: 72b621c2df7ead762a57e1f1d62f286f88f6951c SHA-256: 25e4923948b9d8033f244709dc09c12bfbd20eaf392bd0ff3fd55541ef904747
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous external URIs pointing to disposable hosting. The document body is heavily obfuscated, but the presence of embedded URLs and the link farm heuristic strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 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.
  • 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://philabc.ru/uplcv?utm_term=non+finite+clauses+exercises+pdf PDF link annotation
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/ac86ba6d5ec9a0671f59a393e058b486/nizudo.pdfIn PDF document text
    • http://abyss.sk/userfiles/file/davuwovikolupodowo.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/godowok.pdfIn PDF document text
    • http://dreambeauty.kr/upload/fckeditor/file/juvaduduneb.pdfIn PDF document text
    • http://dsagco.com/Upload/file/3712836636.pdfIn PDF document text
    • http://vindindex.nl/images/uploads/79467958802.pdfIn PDF document text
    • http://ohappy.org/userData/board/file/wedodejabirafix.pdfIn PDF document text
    • http://fcv-bo.org/data/fcv-bo/userfiles/file/xujudubaxatalijogit.pdfIn PDF document text
    • https://hunglivet.com/uploads/files/202109211518561534.pdfIn PDF document text
    • http://email-database.info/userfiles/file/fizabet.pdfIn PDF document text
    • https://spheresignal.com/app/webroot/userfiles/files/wemusigamujanitegiv.pdfIn PDF document text
    • http://mfcwestenkwartier.nl/beta/userfiles/file/fazolu.pdfIn PDF document text
    • http://pro-customer.de/userfiles/file/62711132074.pdfIn PDF document text
    • http://www.velkoobchod-man.eu/ckfinder/userfiles/files/pilogipatuvofuwixumidiv.pdfIn PDF document text
    • http://cottoneauto.it/userfiles/files/juxafomifabine.pdfIn PDF document text
    • https://foodphotoshop.com/userfiles/files/22902123756.pdfIn PDF document text
    • http://alpinedelhi.com/userfiles/files/temat.pdfIn PDF document text
    • https://commonlawhouse.in/userfiles/file/77645969499.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/31750850155.pdfIn PDF document text
    • http://zhongyuemedia.com/filespath/files/20210919191151.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/dulidodupekafe.pdfIn PDF document text
    • http://dsagco.com/Upload/file/54369839593.pdfIn PDF document text
    • http://vigova.com/Images_upload/files/jividutumurowezalo.pdfIn PDF document text
    • http://alliance-ic.ru/uploads/file/71769753644.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_off0000cb3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB3B 17764 bytes
SHA-256: a1f74f599979e1f5069e2fc110e2ddf07b9e04322a2222ff75bbcb37ec135f6d
font_01_sfnt_off0000f923.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF923 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001113a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1113A 10792 bytes
SHA-256: c8d618bcf8869b8cec46bb359a7cc07d070dc254897734a3f92ba2a6d1ce5f37