Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c5f70a491321e38…

MALICIOUS

PDF

85.5 KB Created: 2021-08-19 15:36:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 05744486a3813d0f3b9fb835d5d8e15f SHA-1: 7b6f3df7ae3da4f0d9a1abfee607f2bff9f37581 SHA-256: 3c5f70a491321e389e369e936a7bd766a9869a4f55408d117388783419100db4
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The file functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and disposable hosting, likely intended to lure users to phishing pages or download further malware. The presence of multiple external URIs and the link farm structure strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 6

  • 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.
  • 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://krisoc.ru/uplcv?utm_term=how+to+pass+hesi+exit+exam
    • https://bfull.ru/uploads/files/55209613522.pdf
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e530e0af5db---wasununewulojinematufit.pdf
    • https://vico-immobilien.com/ckfinder/userfiles/files/janofajexodozaluziwi.pdf
    • http://sanchariglobal.com/userfiles/file/35392568258.pdf
    • http://hillhouseclassof1961.com/clients/c/c9/c9b049383fb65e98d0a4dcab6c176392/File/vikodurika.pdf
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/1e4493a2e2b04d848a90f6fcaacf18df/10747926514.pdf
    • https://aradovan.com/userfiles/file/kerujirexezo.pdf
    • http://ippinnudon.com/uploads/files/22473366385.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/21f61203d9a14f2e7b2d703e830af4a1/runododapujavinusig.pdf
    • https://pensiuneavlasin.ro/wp-content/plugins/super-forms/uploads/php/files/osgeaerl2ue91el714nuktslmd/jasosafafaximaf.pdf
    • http://www.mostenpo.jp/userfiles/files/48745668553.pdf
    • https://gresathouse.com/wp-content/plugins/super-forms/uploads/php/files/a535ef868054af66456fcd8e305ca379/77875617348.pdf
    • http://www.deco-interieure.com/userfiles/file/48491255479.pdf
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/caa6501eb0d8a5c31065dfb10689a600/4066724946.pdf
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/1897a0383f222e498137b98ae334c48b/mudewewujuvuziv.pdf
    • http://lideparts.com/userfiles/file/1629336878.pdf
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1609ca1e061dac---tupobop.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608cfddba76bb---40507797357.pdf
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1608189f49ab9e---57547718367.pdf
    • http://www.mostenpo.jp/userfiles/files/62686462589.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077a6cf58488---92533900328.pdf
    • http://condosworld.com/abisol1/userfiles/files/vovilig.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_off0000e80e.bin
4973ac62130b4d72e95df9a72a825e287e80a136a93e6f3689742fc39d519c94
pdf-font-stream PDF embedded font (sfnt) at offset 0xE80E 17628 bytes
font_01_sfnt_off000116b0.bin
a7981c757cf3039b415acce559961ebfb17e4a5838dc21166878e6f60319b147
pdf-font-stream PDF embedded font (sfnt) at offset 0x116B0 10448 bytes
font_02_sfnt_off00012e80.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E80 16792 bytes