Malicious PDF — malware analysis report

Static analysis result for SHA-256 cac38f2d88eb309f…

MALICIOUS

PDF

73.5 KB Created: 2021-09-19 21:32:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: effe6dc535da53b0caf94d1f53aa51fd SHA-1: 2eedd795a555e35e300686195be59f7580a2c8db SHA-256: cac38f2d88eb309ff15578a3b2cb9a8c1b5d225a7a0ecdb013df70e0dc43b72d
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and a high number of external URIs, many of which are part of a link farm hosted on disposable domains. This suggests the document is used to distribute malicious links or for SEO poisoning, potentially leading to further compromise. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=android+1+sniper+3d PDF link annotation
    • https://alquimia.in/admin/fckeditor/editorfile/mipiwo.pdfIn PDF document text
    • http://reklamavysocina.cz/UserFiles/File/tuvovamezamexadopujebe.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/jidot.pdfIn PDF document text
    • http://shiinamotors.com/js/upload/files/bonupo.pdfIn PDF document text
    • https://fereshtegan.net/basefile/fereshtegannet/files/gufusidarivex.pdfIn PDF document text
    • http://conniecorsentino.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/visomiwuxazimusova.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/fuzinagamopilixotat.pdfIn PDF document text
    • http://www.halpellet.hu/userfiles/files/daseme.pdfIn PDF document text
    • http://brbud.pl/userfiles/file/14650481519.pdfIn PDF document text
    • https://citronixdeflection.com/nbloom/fckuploads/file/21874939407.pdfIn PDF document text
    • http://airmon.hu/images/files/likifunola.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/99862001585.pdfIn PDF document text
    • https://santchavarabed.in/ckfinder/userfiles/files/muwiberosizifonet.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1613ead3fa6138---41764830737.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161436a0f20f8f---11382449726.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/rexevapot.pdfIn PDF document text
    • https://pensiuneaselina.ro/userfiles/file/92996335207.pdfIn PDF document text
    • https://creativekids.abcedukacji.pl/web/uploads/files/zekapebasumaz.pdfIn PDF document text
    • https://dudikom.pl/userfiles/file/bawuwowevodetixof.pdfIn PDF document text
    • https://www.ruchya.com.tw/upload/files/65258792890.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/59amtnm5agjefo7opbc4hu0g3n/56080148524.pdfIn PDF document text
    • https://tuvanthietke13-5.com/webroot/img/files/19169656546.pdfIn PDF document text
    • 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_off0000bdfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDFB 16996 bytes
SHA-256: 1117ffddf22d0e5cfabf2b7f94ce420fc98af078056d0589eacec0779a48c0f3
font_01_sfnt_off0000e989.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE989 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000101a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A0 10284 bytes
SHA-256: 3608b6e1c3832bcecd5281c9b75fbe42c32b9b861e7bbdb7900b0001a65e6d3d