Malicious PDF — malware analysis report

Static analysis result for SHA-256 837b95382a0c4a47…

MALICIOUS

PDF

101.9 KB Created: 2021-09-04 09:12:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 604ac389a950a26f9c844cdbf5efcd6a SHA-1: 12c211bbc85c229c103bfb456de4347ed5c9c509 SHA-256: 837b95382a0c4a47a2accdfb4f31b44c9b6d616bbab1f13789015689f0575914
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs and links to compromised WordPress upload storage, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest 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.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://crysiq.ru/uplcv?utm_term=sitecom+homeplug+500+mbps+manuale+italiano
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/ce8e00bd11b57ced41a7d919c490c63a/59186935601.pdf
    • http://harringtonandlombardi.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/lapuzivatadoguxaxi.pdf
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160ad88d17df90---25026578690.pdf
    • https://vadihosting.com/calisma2/files/uploads/24751368146.pdf
    • https://www.elementstraining.co.uk/wp-content/plugins/super-forms/uploads/php/files/7najevuh7n3agb211jc9ec2iec/rosupeweduruz.pdf
    • https://baileyelectrical.services/wp-content/plugins/super-forms/uploads/php/files/9etjkbgpu02nnojrfhilrr168q/koserokobudoxedo.pdf
    • http://spostojow.pl/userfiles/file/figinobulemowufemon.pdf
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160886961a50b2---wiwutinorudax.pdf
    • https://matrainagycsalados.hu/userfiles/file/11688284996.pdf
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac83140638---10715616832.pdf
    • https://deshpanday.com/ckfinder/userfiles/files/33466517886.pdf
    • http://www.saraviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a191d9188c5---63034818963.pdf
    • http://komputerzagrosze.pl/userfiles/file/vadomadide.pdf
    • http://zae.me/datafiles/file/konofixowexin.pdf
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/ae3fd3f862cc6c39db8b14e8025c88fa/jagepifufunuz.pdf
    • http://ladue62.com/clients/2/2d/2d0487a90c18d3a1b3df44839405a665/File/64173321100.pdf
    • http://chongros.com/userData/board/file/19863615811.pdf
    • http://zetrade.cz/userfiles/file/34251761162.pdf
    • https://buffinvestment.com/upload/ckfinder/files/64622373.pdf
    • https://clickbox.ro/images/file/44535714919.pdf
    • http://ichieh.tw/uploads//files/202108110550253209.pdf
    • http://kolesnikov.pro/ckfinder/userfiles/files/98907807490.pdf
    • http://lisaarkin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sijaladexo.pdf
    • http://cerrutistudio.eu/userfiles/files/18101335801.pdf
    • 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_off00012889.bin
35007fb04523f8776c9a8a7b02998fd8f708b92635042bc98a64408e8b78f804
pdf-font-stream PDF embedded font (sfnt) at offset 0x12889 18088 bytes
font_01_sfnt_off0001571c.bin
37176d573ea0ff0227243ef4438b1a880c87997fba32f42ddb9222d6a45d16da
pdf-font-stream PDF embedded font (sfnt) at offset 0x1571C 11292 bytes
font_02_sfnt_off0001713f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1713F 16792 bytes