Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4b6ca634ae5e231…

MALICIOUS

PDF

91.5 KB Created: 2021-06-27 09:08:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 576694abbec08cc31a8ae6877fb96d97 SHA-1: 450011b67d47de6179beae6ebc05467e2b23f47a SHA-256: b4b6ca634ae5e231e06c1d4560781b7fc293af38ae6cca90b188ff0eb80b63be
156 Risk Score

Malware Insights

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

This PDF was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file contains numerous links to external websites, many of which appear to be hosted on compromised CMS platforms or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this. The primary attack pattern involves directing users to external sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://ketchas.ru/uplcv?utm_term=hold+my+hand+hold+my+whole+life+too
    • https://frontlinetherapist.com/wp-content/plugins/super-forms/uploads/php/files/5657914fcd1ca1022fe47f2f1a31dd1a/86515417795.pdf
    • http://lapawan15.com/shop/fck_file/file/75208812162.pdf
    • http://akkoryazilim.com/userfiles/file/66813979934.pdf
    • http://solamsys.com/userData/board/file/4093353622.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b388db2c4c9---bogenoregozanakigorumeme.pdf
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608efe5676617---77780458006.pdf
    • https://advantagelic.com/singhania/downloads/file/giwonepumawida.pdf
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba7f848f855---27058306741.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/16086d37460e8f---buselomaretuposako.pdf
    • http://worldcar.jp/userfiles/files/69914264732.pdf
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/mlq05she7fcefrb91je7hh1ovr/poxizalasovepanitinuja.pdf
    • http://angarakshaksecurity.com/userfiles/file/tunomuwuvuxijotilora.pdf
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609834772a77c---1868315998.pdf
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7c38cd466---rawovogovenisap.pdf
    • http://woodbridgeabw.com/uploads/files/449242163.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/f6d4dab89531f30fa1007921cf9deb4f/lunimezofen.pdf
    • http://bilmatbasim.com/userfiles/file/norud.pdf
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160971f5a34dd3---zijafexutetovenijawevamof.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/35824537732.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a06c4aaf8bc---dojuguma.pdf
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/slgfsi6kfs6f599j9sv36kt57v/42565546908.pdf
    • http://copelandreunionla.com/clients/6/66/66f6f3de7053633686652f51c4c00696/File/bisovakenig.pdf
    • http://dailygiasi.com/uploads/userfiles/file/69640155504.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_off0001056f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1056F 16792 bytes
font_01_sfnt_off00011d81.bin
736f6caf2c26940640ce3adc3f79ba13f21c8217a05337c5df3a657c9564aa66
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D81 16772 bytes
font_02_sfnt_off000148e7.bin
ca2ab4529107c4fa7a916d8cf2f42628b521cf87597e56cbd954e3207a23ad19
pdf-font-stream PDF embedded font (sfnt) at offset 0x148E7 10544 bytes