Malicious PDF — malware analysis report

Static analysis result for SHA-256 d57acf3ea77ac1f7…

MALICIOUS

PDF

79.1 KB Created: 2021-09-14 19:05:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 78f427ebc2e4e1d2f89561e555100401 SHA-1: ddf0731293d34e3ec08f7a03d74e725938b7d56e SHA-256: d57acf3ea77ac1f7316381e576cb875c2462f5eca588209b7b5713edf76b7cde
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to disposable domains, and is flagged by heuristics as a link farm designed for SEO manipulation. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. While no scripts were extracted, the structure and URL patterns suggest an attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9904

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://west-holding.com/userfiles/file/45908686424.pdf In PDF document text
    • http://zezoalza.com/ckupload/files/46729427199.pdfIn PDF document text
    • http://share-world.tw/userfiles/file/1530138297.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/matuki.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/dilepasupobemodebofipez.pdfIn PDF document text
    • http://flexinform.com/hirlevel/file/bukufexavefixon.pdfIn PDF document text
    • http://riverside-plaza.com/upload/userfile/files/69041251417.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021091416281235.pdfIn PDF document text
    • https://sapsda.com/SapmaUserfiles/file/sozis.pdfIn PDF document text
    • http://www.arborvitae.cz/ckfinder/userfiles/files/79547080714.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/55677851887.pdfIn PDF document text
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/42637224147.pdfIn PDF document text
    • http://onnetsolution.in/userfiles/file/zejazi.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613e21198a9fa---zofulitazobuf.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/3853681ece4dc4a13bf43aeaa1723035/47723169429.pdfIn PDF document text
    • http://anais.terminarz.online/kosmetyczka/krakow/files/1063762420.pdfIn PDF document text
    • https://aiwcecckolkata.org/FCKeditor/file/letonira.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210905055625.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/46031291981.pdfIn PDF document text
    • http://sklenicky-obchod.cz/web/admin/fckeditor/userfiles/file/77545928099.pdfIn PDF document text
    • http://puzynowska-kancelaria.com/userfiles/file/86641649349.pdfIn PDF document text
    • http://chanakol.com/ckfinder/userfiles/files/rawereropomalur.pdfIn PDF document text
    • https://nucamsa.es/userfiles/files/koduxatana.pdfIn PDF document text
    • http://fuhua.tumujike.com/assets/upload/files/202109032121182403.pdfIn PDF document text
    • http://muszempilla.com/files/file/buwegeje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=jazz+guitar+sight+reading+exercises+pdfPDF 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://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_off0000d3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3AF 10984 bytes
SHA-256: fa52982cbfbe2b2ea0f60846bc2459ad61311e46e13d7f036c902b762fd1c224
font_01_sfnt_off0000ed05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED05 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10517 17600 bytes
SHA-256: 58d2cb2483ab095dc7e1af575f377c06c3769867131e961100b2695e6705a40e