Malicious PDF — malware analysis report

Static analysis result for SHA-256 f40fb3d09bc2f42c…

MALICIOUS

PDF

71.2 KB Created: 2021-10-05 16:13:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2832391f058f8911d867513fcc62badd SHA-1: 8acf9a9cdec416f2d28c003c175458003f9497bf SHA-256: f40fb3d09bc2f42cbb4af667e8a9aa289c12a8a7046d31bb8743f8e57a07fee7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically indicating a phishing or trojan-like behavior. The presence of a link farm pointing to compromised CMS uploads and disposable hosting suggests an attempt to lure users to malicious content. While no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://thietbikhachsanvinhhung1.com/upload/files/91269111915.pdf
    • http://szilasfood.hu/pic_upload/files/misibekademavoxawit.pdf
    • http://bjhtdszdh.com/v15/Upload/file/202195956223952.pdf
    • http://s8radziejowice-paszkow.pl/userfiles/file/vafakusosi.pdf
    • https://yuvasarkar.org/userfiles/file/81854206548.pdf
    • https://normec-cm.com/ckfinder/userfiles/files/jivapedisirosisejefulu.pdf
    • https://pernambucoimortal.com/imagens/files/50811085534.pdf
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16135b70c2d1c6---nagavow.pdf
    • https://taflanelektronik.com/img/userfiles/file/bipoxonenide.pdf
    • http://ukrfirework.com/images/file/ligigaje.pdf
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/16200468733.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/161311da5b7d0b---mefilujulezi.pdf
    • https://yarsan.ru/wp-content/plugins/super-forms/uploads/php/files/02e7a3aa01c9b8773e73f6a122871190/35661806254.pdf
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/c8c85a2291e9d7e0f02108be042468bd/56092200801.pdf
    • http://lingeriedediva.com/UploadFile/file/2021090214084473499.pdf
    • http://sushi-belovo.ru/files/zebafigarajut.pdf
    • https://movimientofamiliadejesus.com/images/uploaded/file/93628360843.pdf
    • http://ourpreferred.com/userfiles/files/95112206752.pdf
    • https://dhins.com/testingsites/advantage_aviation/assets/media/file/xebobajukutiwus.pdf
    • http://xn--80age2amlc.xn--80adxhks/pics/images/file/lofujofujerawilexenonevi.pdf
    • http://juditphotography.com/picture/userfiles/file/gisareburapejedaw.pdf
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/2d52cc49f7892454f121ec3b460e49b8/fugiwaw.pdf
    • http://notar-frings.de/userfiles/file/relipojavubitivakikisuvov.pdf
    • https://skykharchono.mn/editor/files/5529370097.pdf
    • http://pileki.com/imgup/file/gekazagamagit.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=can+you+get+ink+out+of+leather
    • 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_off0000b874.bin
c7da18d17ecf68265cb331478b1f2ab51835f3c17ca625a9e85ff0945a19fcf4
pdf-font-stream PDF embedded font (sfnt) at offset 0xB874 15136 bytes
font_01_sfnt_off0000de6d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE6D 16792 bytes
font_02_sfnt_off0000f684.bin
16ef4543af387e63ddb1e87c7fe700a006872e34fc4ab6eaf5ecf54b085f9537
pdf-font-stream PDF embedded font (sfnt) at offset 0xF684 10660 bytes