Malicious PDF — malware analysis report

Static analysis result for SHA-256 35b73222a7f4fba5…

MALICIOUS

PDF

76.5 KB Created: 2021-09-09 02:10:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 457298c93eea96485c1c0422cc3f41a9 SHA-1: 034f3791e820d9e842544ee461958bd84d284a37 SHA-256: 35b73222a7f4fba5bd3893767b5e4ee2c83a7be135e7d20251577f9800faa908
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which are identified as compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and does not provide direct textual clues, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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 http://clear-es.net/yamituki-n/uploads/files/wedape.pdf In PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/88572278201.pdfIn PDF document text
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613407087553a---73295399979.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/lunofogojiboluzujiva.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/161392f47def37---9070480111.pdfIn PDF document text
    • http://flooroverstock.com/admin/userfiles/file/wodebakewa.pdfIn PDF document text
    • http://eotp.info/sites/default/files/fck/file/48718050501.pdfIn PDF document text
    • https://taumed.kz/upload/2021/09files/210908001353134187poxfr.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16131749a42238---86297783016.pdfIn PDF document text
    • https://rcot.org/userfiles/file/86337083888.pdfIn PDF document text
    • https://khoahoc.timviec365.com/picturesfiles/wekisi.pdfIn PDF document text
    • http://radyoislam.com/resimler/files/38708516527.pdfIn PDF document text
    • http://eros-arena.de/eros/userfiles/file/92235022719.pdfIn PDF document text
    • http://business-plan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/jamivukipofezetuxe.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133bf21136ea---60918965078.pdfIn PDF document text
    • http://montpellier-businessplan.com/mbp/upload/images/images/upload/ckfinder/jigigebabusulapoj.pdfIn PDF document text
    • https://valleyrentals.com/userfiles/file/busivulifub.pdfIn PDF document text
    • http://viorina-deko.com/images/file/jukimebaden.pdfIn PDF document text
    • http://minhanh.com/files/watowarubujuxuru.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/po16sb11r2aplr2hbhhos7uqn0/68806063942.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=pelicula+la+sombra+del+reino+completa+en+espa%C3%B1olPDF 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://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_off0000c297.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC297 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000daa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAA9 18072 bytes
SHA-256: e5530f70807f690460dfff8831e266d6f0fc67f8bcd3a5c35b96c51cd8b43041
font_02_sfnt_off00010887.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10887 11120 bytes
SHA-256: 695266eb111fdc7a970c555833b81495c890de7bfb6091091f9d72e89cde9b36