Malicious PDF — malware analysis report

Static analysis result for SHA-256 77cabe583d48ef5d…

MALICIOUS

PDF

74.1 KB Created: 2021-06-20 19:07:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ae91371c582350fb2e1af4025f0eb2e7 SHA-1: 1197ca5be62f554c6bf0e43cfc74eeb15bc7d0b7 SHA-256: 77cabe583d48ef5d026ecee79c8e00d13a7f6d38a14b25e9149ac5c0b8d0585c
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document, potentially leveraging embedded JavaScript for further actions.

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 http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16098850edc258---varerekobibulaj.pdf
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b457e29717d---39803597514.pdf
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/bsqetkk0scuvn4j7k346gc7n48/16054106246.pdf
    • https://lerong.vn/wp-content/plugins/super-forms/uploads/php/files/4b785412de09b940998fa46555b725f1/65064740478.pdf
    • https://advancedcheckcashadvance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f71d777665---seleliposuvuwuvipepam.pdf
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/49140bab37ff800b54faba20b46dec49/60620849300.pdf
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/sr7u6suk5dnulqc0hd0vcfjgah/givejuxotal.pdf
    • http://alliusie.com/userfiles/file/rukejeguzepoxaxobabufole.pdf
    • http://banghetretunhien.com/media/ftp/file/tugitaguwirenasiragivaluv.pdf
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/smtjrq7570lfc9q9854f8pnn8p/42621529792.pdf
    • http://superfishinglewood.com/uploads/files/titonevilubunosex.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e38ac0a8ed---79006371770.pdf
    • http://apexibd.com/uploads/fck_uploads/file/vorenekejax.pdf
    • https://lescourailleurs.com/upload/editor/file/42576692635.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b1e993deb2a---37865005910.pdf
    • http://ever-pioneer.com/upload/files/51174100202.pdf
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/gmekb9ltdjo57epnifr892223j/tigawagiwapilovafimuz.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/dbf99d2dac82e9a43cedff8e4f81651d/98955944256.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/9a3a055285eaf1603312347bdec2835a/15811461612.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=pdf+app+windows+7
    • 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://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5aa.bin
e7566a0e97549187be71dd7dd21eca5813acbb2fc2539a762b76a538bebe1a2e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5AA 5080 bytes
font_01_sfnt_off0000f729.bin
63eaa5810c4d308db125aaee9bf208072f6433e0f9a6f437888a0fbd401e00cf
pdf-font-stream PDF embedded font (sfnt) at offset 0xF729 10660 bytes