Malicious PDF — malware analysis report

Static analysis result for SHA-256 824471c4e64e2091…

MALICIOUS

PDF

69.2 KB Created: 2021-09-27 03:48:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c6db7321fca7de5fe0337fe28278282a SHA-1: fd6307f0ce4154e19ad567cbf983777450a376ab SHA-256: 824471c4e64e2091ae2c2d48c03764f0cee054094442fe048b1cbf316efd09e9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress upload directories, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. The embedded JavaScript is likely used to facilitate the redirection to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 7

  • 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.
  • 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 http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/161363cb91aee1---sawuluze.pdf
    • http://ubestsports.com/imager/files/20210921215814.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142123ae6a7a---97744987198.pdf
    • https://ihappywash.com/uploads/files/202109082050592641.pdf
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/13097671088.pdf
    • http://seanmore.com/userData/board/file/birug.pdf
    • https://knurussian.kr/DATA/upload/files/202109011011342042.pdf
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/goranavomufavomuluwixoxi.pdf
    • https://semagro-msw.ru/pics/images/file/zadigukaxagupatumoruz.pdf
    • http://eventologia.com/userfiles/files/bibivas.pdf
    • https://arerp.kr/data/file///14879950936.pdf
    • https://mimpishio.com/contents/files/viwawavi.pdf
    • http://nickels.design/ckfinder/userfiles/files/xazumokamikinokabej.pdf
    • http://ct-tci.com/cttax/userfiles/files/ronavo.pdf
    • https://blagoustroystvo24.ru/ckfinder/userfiles/files/dodoxofojorowu.pdf
    • http://eca.or.th/ckfinder/userfiles/files/34390388199.pdf
    • https://webmodeli.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130856130f34---rerozajivewazelujejeg.pdf
    • http://yokohama-model.com/userfiles/files/20971332421.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147be8c50e1c---getap.pdf
    • https://bulgariapools.com/contents/files/70563412849.pdf
    • https://imad0c0.com/js/ckfinder/userfiles/files/xopumomimubivaluk.pdf
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb8225ee4b---80391083617.pdf
    • http://seteo-dechets.com/images/file/92016048306.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=unblocked+song+sites
    • http://pro.ovh.net/~tribuene/images/banque/file/66474232326.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_off0000af83.bin
efada5bc3db625f1fcf2a65ed0e8386a27028848ed24a96924108ce9f95f430b
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF83 10520 bytes
font_01_sfnt_off0000c758.bin
74fec676d44de1037ec81dc7cb34f6113303c22319a3083ef0ee11a3057fa773
pdf-font-stream PDF embedded font (sfnt) at offset 0xC758 15208 bytes
font_02_sfnt_off0000ed8d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED8D 16792 bytes