Malicious PDF — malware analysis report

Static analysis result for SHA-256 86c8635b5256a3bf…

MALICIOUS

PDF

80.7 KB Created: 2021-09-20 16:34:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: eea87ef046deeef01997e8dba965c50e SHA-1: 921c514df74d113fc1fec8819c9685777854f5fa SHA-256: 86c8635b5256a3bf6976ff003ec8a50e05917f40f37d0f6d96ec592ee8e7b2ad
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to various domains, many of which appear to be disposable or compromised hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's primary purpose is to host a large number of links, potentially for SEO manipulation or to distribute malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://queure.ru/uplcv?utm_term=8+ball+pool+hack+trick PDF link annotation
    • https://tiemhoahaibara.com/data/dulieu/files/todufinixenizu.pdfIn PDF document text
    • https://syntellect.ru/Repository/file/88046085103.pdfIn PDF document text
    • https://kvizek.hu/ckfinder/userfiles/files/60388674525.pdfIn PDF document text
    • https://www.prieur-equipement.com/ckfinder/userfiles/files/92716931860.pdfIn PDF document text
    • http://xn--939a66v0zjo3bcvdmrp.com/data/ckfinder/files/gozijusuwamozegefazuxifu.pdfIn PDF document text
    • https://shunnasato.com/99302999248.pdfIn PDF document text
    • http://ifa-astrologie.de/userfiles/file/89344463717.pdfIn PDF document text
    • http://automsystem.com/UploadFile/file/20210910233504328.pdfIn PDF document text
    • http://compow.net/ckfinder/userfiles/files/tivamixosawojepiji.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/64404558522.pdfIn PDF document text
    • http://dailycan.com/userfiles/files/luvegeri.pdfIn PDF document text
    • http://infracsap.hu/files/file/69346211142.pdfIn PDF document text
    • http://sportsgarten.com/editorData/file/werax.pdfIn PDF document text
    • http://hugslock.com/app/webroot/img/files/72775058836.pdfIn PDF document text
    • http://singlesync.com/userfiles/file/pobozagipalakidapodas.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/r68npc6bmgppa26cipe20pv632/bebubamazabopuv.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/gopurig.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/calm06t3b5v9rhpsfust1frlkm/1361168843.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359276b90ca---lewawexet.pdfIn PDF document text
    • https://izr.fr/files/nizik.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/vebasewagozedobak.pdfIn PDF document text
    • http://creationart.hu/files/file/51549281120.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_off0000d853.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD853 17996 bytes
SHA-256: 20b2a94eda1212aec0af8926c1a48ccad744d454e51e29a7cc53a11709ac0e93
font_01_sfnt_off00010613.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10613 10412 bytes
SHA-256: f75371c355a429f94946c2e752c2fc44c0a90b20cacfc031538ad96e06f49520
font_02_sfnt_off00011d8c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1