Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5c839e661afe4b7…

MALICIOUS

PDF

93.8 KB Created: 2021-07-01 21:00:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d21a1eff82d3b5b47d93cb0af8e1b824 SHA-1: 78ca86db27ba598158b4750e89da8265d46a4483 SHA-256: c5c839e661afe4b76528468ab473b9b2ab39ce3221ce2899b4723b69896cc320
156 Risk Score

Malware Insights

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

The PDF contains numerous links to compromised WordPress sites, indicating a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a89f97cf6de---58237151986.pdf
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/1608ed385cca9c---sizesezozinevibikevugi.pdf
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac5d976b392---binenud.pdf
    • http://xn--l3cbpp3gh4a5g5c.com/userfiles/files/94396456105.pdf
    • https://decoveinvestment.com/userfiles/file/nefozudepaz.pdf
    • http://baybayankaauamo.com/clients/c/c9/c9e0f772d4a556598cfa564a27137582/File/11359403465.pdf
    • http://zwickerfoto.hu/_user/file/91740334247.pdf
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/tbl0lapr7lpmg3gh4bditm7m43/tixiko.pdf
    • https://atphp.ch/userfiles/file/40915492297.pdf
    • https://tonitomov.com/picture/file/17383210059.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/4912276bdb097c17d5587022bd3a8056/rumulinarusitag.pdf
    • https://omomediacion.com/wp-content/plugins/super-forms/uploads/php/files/ce0b4717cb56fb57f3810c09512cf91b/lozetexojowelazuxerodadaz.pdf
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/angdbt097s1iud5t9n4q7j8eb6/wuxafudokadakaju.pdf
    • https://elitteaccesorios.com/wp-content/plugins/super-forms/uploads/php/files/u30tat4jmouto8iv9pdfmktnmq/vukivabubarapisovejik.pdf
    • http://rollfactorytogo.com/uploads/files/49996637500.pdf
    • http://agendatourvietnam.com/hinhanh/file/76943646785.pdf
    • https://www.reliancecareuk.com/wp-content/plugins/super-forms/uploads/php/files/92ce100ddac621c4723aef13d55e1249/nituwekij.pdf
    • http://turhantur.com/turhantur/files/8735566933.pdf
    • http://treeoflifetolfu.com/clients/0/07/07f122ebb3396bb3f917f2e62af81596/File/40069676637.pdf
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/tett0vfkmn764t1nk58cuk57f7/witanuzamutoxeloweregul.pdf
    • http://peaceinsrilanka.lk/userfiles/file/44243355168.pdf
    • http://holycrossyouthministryasp.org/clients/f/fa/fa15eac34f6f8ef5a8ada011ffef1578/File/10331743379.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=lactated+ringers+blood+transfusion
    • 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_off000108bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x108BB 16792 bytes
font_01_sfnt_off000120d2.bin
1e35f4eaf7c9dc4fe1a66d6eb8740ab34bccbc468e4c34ba7ca248d7bb4dc3ba
pdf-font-stream PDF embedded font (sfnt) at offset 0x120D2 10848 bytes
font_02_sfnt_off000139c2.bin
2392ff0b2df0c12052b71f6ea1a3f7f8416ca7b2e7ff09c1b1bbe9c6320d85bb
pdf-font-stream PDF embedded font (sfnt) at offset 0x139C2 18244 bytes