Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac7a3e772140e858…

MALICIOUS

PDF

73.3 KB Created: 2021-08-20 11:10:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 8674b03b6c3320ce5bf66f1582cbf363 SHA-1: 3f530c668963de2cab4ef7cf9201cd53bfe30af6 SHA-256: ac7a3e772140e858c29d14b97ae17577b96fab5b875ba1b689ed1cddd1b35319
156 Risk Score

Malware Insights

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

The PDF file contains numerous links, many pointing to compromised WordPress installations, suggesting it functions as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for SEO spam or to distribute further malware. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9915

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://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/oa6c40vvbafikudd4k1mqnea45/72947146785.pdf In PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/16073a5f5cdfca---22927246220.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081359991a74---78231921511.pdfIn PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/pe1i3g9c6glsr3lkbc7kac42sr/28651668971.pdfIn PDF document text
    • https://akemi.ro/hirek/file/57434243954.pdfIn PDF document text
    • https://www.hippocratio.gr/ckfinder/userfiles/files/77724728480.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/cjlpbsbt9n9kornk37qt5mdg00/1266413454.pdfIn PDF document text
    • http://xinyuemu.net/assets/202106/files/20210616172155114428.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/lefelonafuj.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/c6613482319e2fb15d56434c7e061842/lunababalexujizod.pdfIn PDF document text
    • https://primeodontorj.com/wp-content/plugins/super-forms/uploads/php/files/dc4073dad5999ae391b6db637f53ab49/13474853036.pdfIn PDF document text
    • http://alfavit.tv/userfiles/file/28298303392.pdfIn PDF document text
    • https://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/9oba9smtmfk8vi6d74rmv41akk/27293466808.pdfIn PDF document text
    • http://www.pilonidalsinus.gen.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16083f71caf52a---7270492033.pdfIn PDF document text
    • http://jpcadonate.com/clients/4/48/4863a0bac697dd4b44f4a1b1fb44835f/File/89393755710.pdfIn PDF document text
    • http://dlevitin.ru/fck_editor_files/files/powubodare.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b59ce069dd1---tefidaxox.pdfIn PDF document text
    • http://dongzzang.com/userfiles/file///46092389423.pdfIn PDF document text
    • http://msinziniering.com/userfiles/file/didapugazezofasi.pdfIn PDF document text
    • http://mywayrtk.info/userfiles/file/9610214117.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094a5e877955---sirezexabajaruxisawem.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/2f7d44dca20c94d7c11db1d988202930/60203976072.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bf3b512a6---96372127809.pdfIn PDF document text
    • http://larrysiegellaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/68923366319.pdfIn PDF document text
    • http://gwhs79.com/clients/867100/File/49888664764.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/702636735e9d08de5caa4c861b9344f7/vapataxojevubeposira.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=race+to+witch+mountain+full+movie+download+in+hindi+720p+bolly4uPDF 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_off0000bba3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBBA3 14832 bytes
SHA-256: 9d755cf7b5348bade0a0c4a7f3dd91f7abe7edbef90732b27f76ecc80b837e06
font_01_sfnt_off0000e13c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE13C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f953.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF953 11536 bytes
SHA-256: ac4f54544e71385f59d55144df8165f34f6756f7538efe9c3ccbd671df677305