Malicious PDF — malware analysis report

Static analysis result for SHA-256 b2d963e64181aaba…

MALICIOUS

PDF

80.2 KB Created: 2021-09-19 07:34:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 08e003f38a5e685131af7be1f4700099 SHA-1: f1d2a38879df3c8342ff3d6b5cbe5f3487b3b6bc SHA-256: b2d963e64181aabab3b389cfcc8b1cb820c0035191097fd7d637599eb34a1713
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with several URLs pointing to potentially compromised or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://namngonviet.vn/user-/files/rufososupapupuzofatol.pdf In PDF document text
    • http://hnsunnyfood.com/d/files/81855442554.pdfIn PDF document text
    • https://triosms.com/userfiles/file/78277436999.pdfIn PDF document text
    • https://misbahelmudii.org/ckfinder/userfiles/files/gokewavidosugipabes.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/kuxinimita.pdfIn PDF document text
    • http://patroha.hu/file/jifovoxowevara.pdfIn PDF document text
    • http://top-rubber.com/admin/fckeditor/editor/filemanager/connectors/upload/file/bunedikilikokapemoju.pdfIn PDF document text
    • https://www.alugutader.fr/ckfinder/userfiles/files/nevonifopiriliduzodegoza.pdfIn PDF document text
    • http://eegbiofeedback-leszno.pl/userfiles/file/fubivuxovewufi.pdfIn PDF document text
    • http://muzeumostrowiec.pl/obrazy/file/wopiduw.pdfIn PDF document text
    • https://prospr.fr/ckfinder/userfiles/files/poxoz.pdfIn PDF document text
    • https://xtremefitness.com.au/application/third_party/ckfinder/userfiles/files/91302214775.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/kudedafofafowilimobuxoni.pdfIn PDF document text
    • http://przyrodnik-kujawy.eu/userfiles/file/tokuxolunofon.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/629113537dcff21e6c2b8d31167450a2/3406909405.pdfIn PDF document text
    • http://laboratoriodiprogettazione-ve.it/userfiles/files/16785499350.pdfIn PDF document text
    • http://wm-meyer.de/meyer/admin/editor/ckfinder/userfiles/files/54905028329.pdfIn PDF document text
    • http://membranekeyboard.pl/_data/file/5095381977.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/65693364808.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/16134d64548356---gizigasulabutiba.pdfIn PDF document text
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613921afe4b74---mujibedugunivala.pdfIn PDF document text
    • http://dermalab.pl/userfiles/file/28361341173.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146b92c53571---xulujojuxegape.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/f6d4ea14fd4ce40c47a5e135ef36c28b/32412745565.pdfIn PDF document text
    • http://centralgiving.com/media/userfiles/file/nejobovopatabiputamixus.pdfIn PDF document text
    • https://wic-net.com/userfiles/file/26826137648.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=how+to+stop+vibration+on+androidPDF 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_off0000d550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD550 17756 bytes
SHA-256: 94439b4d83b043fc92ce1f61bf8e320b8072893826d218ec321e41fdb2c7311b
font_01_sfnt_off0001032b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1032B 10488 bytes
SHA-256: 37b0934846138507b17db6c8338657ecbcda019e46c8130daf145c1912c5c2ed
font_02_sfnt_off00011ae8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AE8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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