Malicious PDF — malware analysis report

Static analysis result for SHA-256 9437884f2566eff0…

MALICIOUS

PDF

71.7 KB Created: 2021-06-22 11:47:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-27
MD5: e41ab7048e82a7af610772d28c7e2522 SHA-1: e4e4387d085b575975fd55d28892f238d41121dc SHA-256: 9437884f2566eff092b0008701c08e84ad36c4f8bee9c98db150b46b343e8614
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous links to compromised WordPress sites and other disposable hosting, suggesting a link farm designed to distribute malicious content. The document body, though heavily obfuscated, contains references to 'medical dictionary apk', likely a lure to entice users to download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/tq4mg1np5j1ko4j7ote0pbk28o/sejefasiparuramer.pdf In PDF document text
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/8b64987104de7b3cc991a0d245b532f5/vapaturanikowukizo.pdfIn PDF document text
    • https://1877painters.com/FCKeditor/file/31879279069.pdfIn PDF document text
    • http://elsekmont.eu/userfiles/file/varebaje.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/77436603838.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084bc5579223---lanosewiz.pdfIn PDF document text
    • https://chp-travel.ir/data/file/degitagubumod.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/a97f4b00edf05e8da6b01d9a5ff019b2/wowinasemikakapolep.pdfIn PDF document text
    • https://outsourcedbackoffice.co.uk/wp-content/plugins/super-forms/uploads/php/files/705faa50c3810605fb864f08aaf550ff/50995521205.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/wikarapukamigagoviginuvat.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a747b157c---rafujilazidexubolinu.pdfIn PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/pqumscfgl0o76d14rngo2qlgl1/galutinonalumol.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079dc3b50e37---nisonuk.pdfIn PDF document text
    • http://extracam.es/app/webroot/arxius/file/63628261815.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbfe28a7035---45682159319.pdfIn PDF document text
    • https://anfauglir.com/images/file/68749584132.pdfIn PDF document text
    • http://longarmacademy.net/fckeditor/userfiles/file/fofapewuwiga.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160729bac49e3a---31894665421.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=medical+dictionary+apkPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB0D 5060 bytes
SHA-256: 1851b4adcad85c142c41906e635877da820aebe9f66b0fca8d60654f4e84e73f
font_01_sfnt_off0000ec69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC69 10948 bytes
SHA-256: 934924c131fffecf8f474d2c1a4991261c3b021e60db91babb8f22869a14bfcc