Malicious PDF — malware analysis report

Static analysis result for SHA-256 cb70da76119c7517…

MALICIOUS

PDF

87.1 KB Created: 2021-07-14 05:17:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fbf3c5109977fb4526e29229134023f4 SHA-1: e9979ac3bc4b2322bd1bb09c17bde5ead26d6e77 SHA-256: cb70da76119c7517ed59fbef16de8918f8e4b1f64fc45f9d94cbb4e59b6de8e9
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to distribute malicious content. The presence of ClamAV detection and ML classification further supports its malicious nature. The document's structure and embedded links suggest a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://drafthe.ru/uplcv?utm_term=difference+between+single+threaded+and+multithreaded+process
    • http://hoteldanang.vn/uploads/images/files/79650732186.pdf
    • http://hglobaltour.com/FileData/ckfinder/files/20210610_B6DA716E973F4F41.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/b6764416065d9697f9289ec14752fbe8/17035248120.pdf
    • https://nestaerospace.com/uploads/file/14167982329.pdf
    • https://selectwifi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160978fb443978---setet.pdf
    • http://vizugy.hu/uploads/files/39759630332.pdf
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606d545c9bef6---29111706750.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab0b978fca9---43000463886.pdf
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/9pg1c0n6vp283rjc4vr1buq9v6/81826696066.pdf
    • http://darienhigh69.com/clients/866565/File/wepivirip.pdf
    • http://udclassof1968.com/clients/74076/File/18859523836.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac124662837---1970695364.pdf
    • http://blpest.com/UserFiles/file/kumobuv.pdf
    • http://acmemask.com/upfiles/editor/files/41964240027.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609fd9412036d---9923756331.pdf
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1608a71c6ec306---87201097266.pdf
    • http://allprintusa.com/admin/images/file/8776995598.pdf
    • http://animationcoach.com/userfiles/file/saxedigovefejezasad.pdf
    • https://sesconbs.org.br/ckfinder/userfiles/files/77474917522.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c68de41ed3---wojakivo.pdf
    • https://sonntag-immobilien.lu/userfiles/files/xipegekebag.pdf
    • http://montrealinkwell.com/clients/c/c4/c478fb9048b4d856ed1aa16e2301f982/File/42094760630.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d8da41be9a8---80142405838.pdf
    • http://bjjiffy.com/upload/vekewagaxeri.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_off0000ef34.bin
ad56984bc77ebeba8d4448a4b0168f1be329e20787dc28930219f12706d7c72c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF34 17136 bytes
font_01_sfnt_off00011c07.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C07 16792 bytes
font_02_sfnt_off0001341e.bin
18be4124dc483988dde9c65e8c731ac226917f178f86728db72308dd7a1ce783
pdf-font-stream PDF embedded font (sfnt) at offset 0x1341E 11396 bytes