Malicious PDF — malware analysis report

Static analysis result for SHA-256 7dcc055c77669ff8…

MALICIOUS

PDF

80.9 KB Created: 2021-09-12 03:26:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 18301379de7469b1a1264c45945e5559 SHA-1: aa4a8b0a975a108a306470619d9b3c5d119c53f9 SHA-256: 7dcc055c77669ff8d462d4053647f4260121bee123a4b9fe39ddc2c86ece51bf
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous external URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated, suggesting an attempt to hide its true nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://anaksemut.com/contents/files/wafawujuru.pdf In PDF document text
    • https://htapigroup3.com/contents/files/84198401080.pdfIn PDF document text
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/guxetowukabu.pdfIn PDF document text
    • https://fokusmedia.com/images/uploads/89454905377.pdfIn PDF document text
    • https://seikai.jp/free_images/files/5771467366.pdfIn PDF document text
    • https://thokhoavietnam.com/upload/files/34771377838.pdfIn PDF document text
    • http://xn----7sbezcba9a5aggb3j.xn--p1ai/ckfinder/userfiles/files/10666152517.pdfIn PDF document text
    • https://wodepcb.cn/uploadfiles/files/bitarivujusixudujufepefi.pdfIn PDF document text
    • http://zafirkort.com/uploads/files/80887290749.pdfIn PDF document text
    • http://hcstonetw.com/uploads/files/202109111950224394.pdfIn PDF document text
    • http://smelawservice.com/file_media/file_image/file/pesisekizidasukamunazipel.pdfIn PDF document text
    • http://j-line.ca/fck_upload/file/54207417948.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/20266912590.pdfIn PDF document text
    • https://conexkarvan.com/cache/fck_files/file/49419847403.pdfIn PDF document text
    • https://maconlux.lu/userfiles/files/divigetoruvo.pdfIn PDF document text
    • http://gu-bo.cn/uploads/files/xemekonuzidig.pdfIn PDF document text
    • http://teknis.it/userfiles/files/muvivaderijiwotiti.pdfIn PDF document text
    • http://nasledie-sluck.by/var/upload/file/revipozon.pdfIn PDF document text
    • http://tecresconsolidamentorestauro.it/fck_data/file/bajuwemorubanefanoribeli.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/bezupokeraxew.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/0ickmiditrn629r93lum8o2cvv/nokaturidajugijusabira.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/161345b2c9f8c8---5074914131.pdfIn PDF document text
    • http://hum-lucknow.org/test/fckeditor/file/gipufibiripupowigusa.pdfIn PDF document text
    • https://bilbox.es/wp-content/plugins/super-forms/uploads/php/files/f916b267051f16d5d4a0feec95c7329c/42164932752.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=aplicaciones+android+hechas+en+pythonPDF 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_off0000d6fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FD 10704 bytes
SHA-256: 93697e181436229790a259b99c1286868cbe40114962ac88fc0b12d08df1772d
font_01_sfnt_off0000ef92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF92 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A4 18256 bytes
SHA-256: c875c5bcadbb70cf5a67843b49c764d004c1f8a0e567f936f9cf828cdd2902f7