Malicious PDF — malware analysis report

Static analysis result for SHA-256 28eb372d168f9dc6…

MALICIOUS

PDF

96.1 KB Created: 2021-09-04 08:21:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3282f4415decfdd1ae7a297e77d63c6f SHA-1: 6ec673e772ef5a347bf3bafeb8eefef77c978f41 SHA-256: 28eb372d168f9dc6ecc1b9675515719b2b29b0287f3b584f15597361f9d89a25
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories, suggesting an attempt to lure users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://ghadir-eng.com/userfiles/files/5841470065.pdf
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6dc848093---86916843891.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6254a003a7fa55038c1e92ae9c5644c8/molubojowowixejoda.pdf
    • http://obchodsezlatem.cz/upload/files/vanara.pdf
    • http://bona-agra.pl/Upload/file/muruwesezikabejapaki.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/160adcb40b7e52---63486077757.pdf
    • https://cortemadera.com/wysiwygfiles/file/kasuwarigozegozosusigetiv.pdf
    • http://studiogiamberardino.it/userfiles/files/51427190885.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b11e396ab39---pekikiguve.pdf
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088b404454e4---sunupuda.pdf
    • http://clair-environnement.eu/catalogue_dynamique/file/mavobuferesudewaluba.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/f7b78132cff1f57add2ca1a28c458e45/buturutanona.pdf
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16085538f78015---rewisunebukuwezafowego.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609092454eb64---dilodanopige.pdf
    • http://vidol.nl/userfiles/file/samagusofejasej.pdf
    • https://surupaceanu.ro/ckfinder/userfiles/files/demowisivufewutig.pdf
    • http://tano-cable.com/d/files/85617440209.pdf
    • https://www.heracles-hotel.eu/wp-content/plugins/super-forms/uploads/php/files/5j4bisht1sfffklh6j2men2tdm/jiwejale.pdf
    • https://fallsplat.se/file/46505910075.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d7c18ee14b---luvagupokafirikotug.pdf
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089a1525ddd7---86299021912.pdf
    • http://peoplefineart.com/assets/202108/files/20210801044635910389.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=exercices+en+java+claude+delannoy+pdf+gratuit
    • 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://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010912.bin
35c16461dc136811acdc23458d3ea4fd53ece704f60be2eae90702c84ec16ea9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10912 21272 bytes
font_01_sfnt_off00013fe9.bin
cb13b87bd3195524bae626a4953dc72b1a7cabdde391114bf9814ca3142f5fab
pdf-font-stream PDF embedded font (sfnt) at offset 0x13FE9 11292 bytes
font_02_sfnt_off00015a60.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x15A60 16792 bytes