Malicious PDF — malware analysis report

Static analysis result for SHA-256 c491775cf78d3be8…

MALICIOUS

PDF

68.0 KB Created: 2021-06-20 17:17:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-12
MD5: 539ace98cf111554d8c0a2294e643374 SHA-1: 01be351a3fc9aacd37e7e3484fbf1ed6a909ab4c SHA-256: c491775cf78d3be80259e2926dc19bbc2c8d595a828f73790f3d2ab7b34e2abf
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically identified as a phishing trojan. It contains numerous links, many hosted on compromised WordPress sites or disposable domains, forming a link farm. These links likely serve as a lure to download further malicious payloads or engage in phishing, consistent with spearphishing attachment tactics.

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://chcial.ru/uplcv?utm_term=convert+two+mp3 PDF link annotation
    • https://manuscripthandler.com/userfiles/file/dimenux.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-2/20210502060436863675.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608eaf7521187---madetobok.pdfIn PDF document text
    • http://cl-pub.com/files/files/16067232215.pdfIn PDF document text
    • https://senhewood.com/d/files/68324589050.pdfIn PDF document text
    • http://ballstonfamilymedicine.com/clients/861402/File/44264602986.pdfIn PDF document text
    • https://locktactyuma.com/ckfinder/userfiles/files/duxabubo.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3cb53e8fd---808842685.pdfIn PDF document text
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1608785045a31c---bitaze.pdfIn PDF document text
    • http://beiks.info/public/file/3213272696.pdfIn PDF document text
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba5d621706c---60022215947.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b6ccc95297d---56966776746.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/a0b2c05536cd998f704f3cd42ab53a2f/sifakuregirudumenid.pdfIn PDF document text
    • https://groupburuemas1.com/contents//files/kibafuxalabexawabemij.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a6e437b6e78---bimelunuvex.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609919211fb80---37926729158.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160c86ab6c1310---40820039031.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c18b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC18B 4624 bytes
SHA-256: f977185c6fb3d6191381369efe79630f46b9fdf8b7e13c491733892824ff733e
font_01_sfnt_off0000d13a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD13A 10228 bytes
SHA-256: bc5669b3a377d92239e11b4e4c298d91c82564e59412e5fa8dfafd82ef265f85
font_02_sfnt_off0000f3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FA 4324 bytes
SHA-256: 7f6049e5011acf0e8581793f2bc2bb947aac2929fdb77abc318b2a6155c1ef71