Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a57ce3161285e03…

MALICIOUS

PDF

87.2 KB Created: 2021-06-25 16:03:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7ab840a33b254b2b07d5f355f88a5c61 SHA-1: 80b0a65ccd7d33a16badc7202c22887da13b86b2 SHA-256: 6a57ce3161285e03a438624e9e3c1291a6255d4b8e3d5b93e6411efb7b377d07
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The presence of multiple compromised CMS upload links further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/bd11693f5b642a5b264493bf8cd6ee13/80000100563.pdf
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160877d1b15401---morekumovu.pdf
    • http://atthaya.com/file_media/file_image/file/21786343784.pdf
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/27447037941.pdf
    • https://aliencosmicexpo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab9424da84b---gugiserejipomasesasazij.pdf
    • https://asiarsolutions.com/userfiles/file/35006917688.pdf
    • https://parokisantolukas.org/Uploads/userfiles/files/60034280863.pdf
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/1e34016a45e4d7ab299b847659079efa/taviwajizodozomivitibexu.pdf
    • https://xo-sound.ru/userfiles/file/bevowedomosotapexar.pdf
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160887c2d91a4b---55183827931.pdf
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b0946e53647---bidabe.pdf
    • http://luvnchrlysenglishtoys.com/clients/861429/File/mugibexo.pdf
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/gle123a724mj4in8bctrh0prtg/37682716123.pdf
    • http://almar-bus.pl/userfiles/file/nikijerorigek.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/pf5al1h8b7v3e7t6k0c97qgumo/70423857397.pdf
    • http://abacusnancy.com/userfiles/file/tigisojudemosepuzateneg.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077d38caa0f9---54903922153.pdf
    • http://darec.sk/files/files/30741537603.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=candy+resource+pack
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db4a.bin
f2a4d31a8c571088e7e80500c7c98a50c1cf6741bac7041026ced70331d41886
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB4A 10608 bytes
font_01_sfnt_off0000f3b3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B3 16792 bytes
font_02_sfnt_off00010bc5.bin
72f3aff958624e87ee27894bcf33c8f3d8150fd09039db071d706d313257488c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC5 17772 bytes
font_03_sfnt_off00013a8b.bin
a013ce2342554bbd70a9f85285a6053b67e9b25eaba0dd22223cc179b1b1ea16
pdf-font-stream PDF embedded font (sfnt) at offset 0x13A8B 16064 bytes