Malicious PDF — malware analysis report

Static analysis result for SHA-256 828f8914528043b0…

MALICIOUS

PDF

114.6 KB Created: 2021-07-31 14:51:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 838b2163ca9a418a374dd90df1f6989f SHA-1: 09458d98279c8fde12b395d846523fd978b9564e SHA-256: 828f8914528043b06eb5e733fb66d7ca5346c633e1fe64a247f08f6421ed3482
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised WordPress sites, a common technique for distributing phishing lures or malware. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as a phishing trojan. While no scripts were extracted, the structure and embedded URLs suggest the document's purpose is to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

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://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/72b7438aaf59eee981738c6a085560ac/74342206288.pdf In PDF document text
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca4ea88c38c---81147033370.pdfIn PDF document text
    • https://cuatudongbinhduong.net/uploads/files/rafugakinoduxel.pdfIn PDF document text
    • http://exactblue.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be58a75e22b---lubibuwo.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160a8fa1dbc7ee---96558069740.pdfIn PDF document text
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/55ad7e667232315014b02557e5ce35e4/xatokanoxetevupun.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/74319328067.pdfIn PDF document text
    • http://edumedcare.pl/upload/files/pojajepazerubeg.pdfIn PDF document text
    • http://narnivet.com/userfiles/files/janipobe.pdfIn PDF document text
    • http://sys-svinding.dk/userfiles/file/40571712035.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/lovufuwugalutivadi.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/160c6a1ab1af34---zumidirogo.pdfIn PDF document text
    • http://bakoca.hu/files/file/sejoxidurorukapurijanigu.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/60845839730.pdfIn PDF document text
    • http://mamaskitchenorder.com/uploads/files/9045981057.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/sosuvemazekofinude.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/xewokebofare.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/49158429597.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085c346ab714---noporefidup.pdfIn PDF document text
    • https://miraclechuppahs.com/userfiles/file/folomol.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/42774854525.pdfIn PDF document text
    • http://ibconsulting.it/userfiles/files/73226563520.pdfIn PDF document text
    • http://mauchlineware.com/html/chapelstreet/web/userfiles/files/petamigifovemogaxamobolek.pdfIn PDF document text
    • http://bacsionline.net/userfiles/file/9664545540.pdfIn PDF document text
    • https://digireg.cz/upload/dojobilemorekoz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=shark+ion+r87+manualPDF 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_off00015cf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15CF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00017508.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17508 18104 bytes
SHA-256: 706d35c1396345d2706ea44ecc52c091ba5d99db706cee90d128927cee1dfd34
font_02_sfnt_off0001a4af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A4AF 10500 bytes
SHA-256: e548ef21eaeb701d39177805509b531bb29b913087faeac71c565660bdd6487c