Malicious PDF — malware analysis report

Static analysis result for SHA-256 8258fc45a8ac77d5…

MALICIOUS

PDF

71.6 KB Created: 2021-09-30 19:52:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3189bb21bf98d9a855d780beafe6141b SHA-1: d51a16752c3ab07d8e0c95ee38d1bbc02aee59f5 SHA-256: 8258fc45a8ac77d548797b46906337162e1c01fa125e14e68a9cc8e259b277f4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many of which are hosted on disposable domains and appear to be part of a link farm, suggesting a phishing or malware distribution campaign. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the PDF is designed to redirect to multiple external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://queure.ru/uplcv?utm_term=mise+%C3%A0+jour+galaxy+note+8 PDF link annotation
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/befexaxanifaxotira.pdfIn PDF document text
    • https://samsungklimalar.com/upload/ckfinder/files/fuwukiro.pdfIn PDF document text
    • http://namlinhchisapa.com/userfiles/image/file/10657869120.pdfIn PDF document text
    • http://lifeisartfoundation.org/sites/default/files/images/userfiles/file/duziwelezejaka.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/16408464145.pdfIn PDF document text
    • http://corkpotters.com/images/21190634039.pdfIn PDF document text
    • http://www.rebranded.tv/wp-content/plugins/formcraft/file-upload/server/content/files/1615392f0d31ee---80137877894.pdfIn PDF document text
    • https://eyescare.vn/app/webroot/upload/ckfinder/files/45945519893.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/25513799528.pdfIn PDF document text
    • http://salonorganica.ru/upload/files/mesojiki.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/22374088758.pdfIn PDF document text
    • http://ranch.pl/files/file/jinujoruwov.pdfIn PDF document text
    • https://aimtronu.org/userfiles/file/34289089781.pdfIn PDF document text
    • https://mygenius.ru/admin/ckfinder/userfiles/files/96035017598.pdfIn PDF document text
    • https://turkuazhost.com/calisma2/files/uploads/lilenejadigasako.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/20889617135.pdfIn PDF document text
    • https://namdolove.com/FileData/ckfinder/files/20210904_F25E41DD15538CA4.pdfIn PDF document text
    • http://danangsculpture.com/uploads/image/files/7615231419.pdfIn PDF document text
    • https://learn-atdi.com/uploads/files/22560805039.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139e9e2ef2e5---84708721821.pdfIn PDF document text
    • http://ppfi-online.com/userfiles/file/75862152670.pdfIn PDF document text
    • http://studiotecnicomaglio.it/userfiles/files/mijonaniweziga.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/90628147615.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_off0000b13a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB13A 11112 bytes
SHA-256: 9708623869e0b3a493a5988f005d56b3105b340c48abc9eea595abce128c160a
font_01_sfnt_off0000caf0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAF0 17392 bytes
SHA-256: d65b1041d3e067ec3f5d01216662b16ba705041f63c9be7bd3ee29fb9eb29577
font_02_sfnt_off0000f76d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF76D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1