Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac5cb9990cc6bc09…

MALICIOUS

PDF

88.0 KB Created: 2021-09-01 04:30:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b4ebfcf37d1191319850aeb724759160 SHA-1: b3f6f6a1531ae0647135ad54f2175e62e35077e4 SHA-256: ac5cb9990cc6bc090a15de8bfa3b46b086b52f5288c635b7bb032998b7435c08
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating it likely exploits a vulnerability or contains malicious content. Heuristics identify it as a link farm pointing to numerous domains, some of which are hosted on compromised CMS uploads or appear to be disposable. The primary purpose seems to be directing users to external, potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://cutyoursupport.com/userfiles/file/jogagoxik.pdf In PDF document text
    • https://zapret-rf.org/web/img/podborky/files/jugizenujuke.pdfIn PDF document text
    • http://kaies.cn/upfiles/210618163935887752h6chrp.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608bbb653ec22---85791203653.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/160888ffd50d21---33975524505.pdfIn PDF document text
    • http://vandientuchinhhang.com/upload/files/63337014673.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ac63309c23---wupobej.pdfIn PDF document text
    • http://thaihotelsale.com/FileData/ckfinder/files/20210803_CD3C6F64F9D3AD98.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090a78e6bbc2---deradokefebejevapebafalu.pdfIn PDF document text
    • https://fibra-optica.ro/ckfinder/userfiles/files/9031753337.pdfIn PDF document text
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/voxakizexojumevusuguxidod.pdfIn PDF document text
    • https://ubranni.com/uploader/files/28483105049.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/3c21e9b56b0a1b9024ee1e10be99b7c2/sufuwerinabu.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/16098344e2133c---fivapurezukujefom.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16081cca895656---112008478.pdfIn PDF document text
    • http://pomodorolennep.de/gfx/userfiles/files/94293244024.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d9f77cc565c---31951644056.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c145bba6a68---xifejufofi.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/9893f105fb23274f1143d3c9407fedd4/nuzogipatonenekepewafusuz.pdfIn PDF document text
    • https://premium-house.uz/images/file/wepinavikuzuzifovu.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acf19aae3a1---zeluberuzisegi.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/86070818491.pdfIn PDF document text
    • http://masterref.ru/editorfiles/file/feguterujoloxa.pdfIn PDF document text
    • https://dptech.vn/uploads/files/modemumifu.pdfIn PDF document text
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b1f33249884---54914268478.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=change+in+position+velocity+time+graphPDF 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_off0000f081.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF081 18428 bytes
SHA-256: 933f4174fd7214b6b280b8768991ad17555079d0c79d21dfe99d6d96ddb9a622
font_01_sfnt_off00012064.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12064 11032 bytes
SHA-256: 42cfc01d491e7e911bf1acfa8259d3d6b147f59d09a86bd3fbcf540118409cee
font_02_sfnt_off000139eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1