Malicious PDF — malware analysis report

Static analysis result for SHA-256 de77bf8ae2aa2ac3…

MALICIOUS

PDF

82.3 KB Created: 2021-09-17 00:30:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3b66861c03ed27030768bf4ac5be9bd3 SHA-1: 819793c5253c22f3686a07312c7aef34a56ce87e SHA-256: de77bf8ae2aa2ac3e47fbd6bfe49d00e9aa1caf0ea26df1153c6468fbad141e6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised websites or disposable domains, indicating a link farm designed to lure users to potentially malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics confirm this behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://sma-dfgg.org/site/admin/file/15147744908.pdf
    • http://ekotop.eu/userfiles/file/17801206676.pdf
    • https://prettygreekvillas.com/admin/fckeditor/editor/filemanager/connectofile/levexalanigiwila.pdf
    • https://mahae.hu/files/files/sirawokomidej.pdf
    • https://mimpiindah2.com/contents/files/73816798995.pdf
    • https://uudanbury.life/files/file/tulaxowusofilebasililod.pdf
    • http://dichvumucin.com/upload/ckupload/files/41161838448.pdf
    • https://madeirashopping.com/userfiles/file/vamiwez.pdf
    • http://zespolbahamas.pl/zdjecia/file/fagenawumifuzufevixux.pdf
    • https://www.hotel-palladium.gr/wp-content/plugins/super-forms/uploads/php/files/bm2ss1jubu3u49f2idemcvuvm3/58860884174.pdf
    • http://oticonshop.com/ckfinder/userfiles/files/85886483474.pdf
    • http://noithatlekhanh.com/Images_upload/files/96206383905.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bd6c1aba81---bijivenuzinuji.pdf
    • http://desushibar.com/userfiles/file/kufoligijamibuz.pdf
    • http://nokianhakkablue.ru/ckfinder/userfiles/files/gomopenad.pdf
    • https://turismopontevedra.com/ckfinder/userfiles/files/39332160019.pdf
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/31e38888d7ca9078efcaf8907b4a5ede/23103618199.pdf
    • http://cpghollywood.com/userfiles/files/rusibiferajimasibixasiv.pdf
    • https://maintogelonline2.org/contents/files/19304230835.pdf
    • http://agriturismocorteerbatici.it/userfiles/files/12317754266.pdf
    • http://dgxzz.com/uploadfile/file/54397431925.pdf
    • http://xinshifm.com/userfiles/file/jozamifufawaj.pdf
    • http://abaj.cz/UserFiles/File/83433287784.pdf
    • https://digireg.sk/upload/69440674039.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=transfer+contacts+to+new+phone
    • http://s292376414.onlinehome.fr/datas/imgmail/file/84615845888.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc5f.bin
da031009d5911d25c661a3571406d230b29d5fdee11cfb985785fcac5f9b528f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5F 18200 bytes
font_01_sfnt_off00010b2b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B2B 16792 bytes
font_02_sfnt_off00012342.bin
273aecdc9728226b011ac49353c85f1aad535b3aff56d1e5c2caf2dfb5767343
pdf-font-stream PDF embedded font (sfnt) at offset 0x12342 10488 bytes