Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a77ca9a0efde9de…

MALICIOUS

PDF

74.8 KB Created: 2021-09-04 13:49:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4194c425e805d7657a7fcf2e3d810f40 SHA-1: 85c4ecf0037ede03786b24ba764e5e1ccf94c2cc SHA-256: 8a77ca9a0efde9de6cda07fbc5b6381e94f919b298038c74456e892edda76c49
156 Risk Score

Malware Insights

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

This 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, containing numerous URLs pointing to potentially compromised websites or disposable hosting, likely to distribute phishing content or further malware stages. The presence of multiple external URI heuristics and link farm indicators supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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://medvor.ru/uplcv?utm_term=hampshire+manual+of+personnel+practice PDF link annotation
    • https://rieker-consulting.eu/files/file/faxuwisotisixol.pdfIn PDF document text
    • http://westmoorclassof1965.com/clients/5/52/52ec68f2b927accf75267cb07bfcc891/File/xotepogakuxusijexizaj.pdfIn PDF document text
    • https://stauber.lt/images/files/xitusuguwozowegope.pdfIn PDF document text
    • https://joyfool.art/wp-content/plugins/super-forms/uploads/php/files/e7c696228de0de4fd80549eb3152e33b/wosufesuzojafokodejaluf.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/83f4a0be41022f05b18d0990dd7b1eb7/wogunuwizenivegi.pdfIn PDF document text
    • https://ewastexperts.com/userfiles/files/faxirixapusozexer.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085dc50be810---11628865724.pdfIn PDF document text
    • http://asea-admin.com/_userfiles/file/20210816073117.pdfIn PDF document text
    • http://kasargod.net/uploads/file/65187348095.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/160835c4726266---wosenij.pdfIn PDF document text
    • https://otartufo.com/ckfinder/tartufofiles/files/44028383215.pdfIn PDF document text
    • http://dieta-plus.pl/userfiles/file/nisozosuwaxemana.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6a37636e1f---sanofis.pdfIn PDF document text
    • http://xn--e1aazeoc7d.xn--p1ai/images/shared/file/setivazodopamizawokisef.pdfIn PDF document text
    • http://magicfood-cn.com/files/20210828181727.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/16126a672ceeba---76325054327.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/kozobunapexifiz.pdfIn PDF document text
    • http://driscollandgibson.com/images/edit_images/file/7472006515.pdfIn PDF document text
    • http://auto-spec.ca/fck/file/vefigoxupimaroxifo.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/dcu70lit4hklsu7d4ctq57lo9l/pejirisefaxuxibepaneza.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c73e386758---gepixarixuje.pdfIn PDF document text
    • https://ceccarmaramures.ro/userfiles/file/dilakusepomububedad.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160715751b4b02---regebezuwatakotu.pdfIn PDF document text
    • http://antichigelsi.it/userfiles/files/50287530964.pdfIn PDF document text
    • http://beijingteye.com/upload/files/lesemo.pdfIn PDF document text
    • http://landia-print.com/pdir/file/99506612270.pdfIn PDF document text
    • http://xn--80adpfaaeictf0c6c7i.xn--p1ai/public/file/sulipapemidopivedosafi.pdfIn PDF document text
    • https://tbsva.org/Upload/files/20210704130126.pdfIn PDF document text
    • 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_off0000c535.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC535 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dd4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD4C 10836 bytes
SHA-256: a578c7b3476edc1e1141ea7e567fe87b8d20de9353a04b548a35398ea058d10b
font_02_sfnt_off0000f60d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60D 15460 bytes
SHA-256: 41ec66a1f2feb08f3d50de26bd52dfe3f004d0d0d06019efeeffd30d044d70b5