Malicious PDF — malware analysis report

Static analysis result for SHA-256 91ad4392a83b44ba…

MALICIOUS

PDF

122.3 KB Created: 2021-06-27 21:10:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: da2b680955e09038f227d637fe75b9ff SHA-1: 9cb0c609fefb60140470338022478527a8f533fb SHA-256: 91ad4392a83b44bac6810f7d6db907a2de5b3e98f9b740fe2af2703db9d74014
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains numerous embedded URLs that point to various websites, many of which appear to be compromised or disposable hosting. The heuristic firings indicate this is a link farm designed to redirect users, likely for phishing or to download further malware. ClamAV detection and the ML classifier strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://philabc.ru/uplcv?utm_term=using+clt+to+find+probability
    • https://smilepath.com.au/wp-content/plugins/super-forms/uploads/php/files/d0cff3f8c5be513d6519d12666f5e211/dubasasegite.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/rj5c0nlde6i1dncsv2026vvcv5/dowelusujuvataf.pdf
    • https://seitonsolutions.com/ci/files/2138967771.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608132e3bb1d7---vuzakadoronivisaru.pdf
    • http://sbnjl.com/userfiles/files/38695842956.pdf
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160ba64892905e---bokagosam.pdf
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1609ab23a2feb9---lefadexekexazi.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/c447e99a448d786f2fee941b9752ab77/tubopowuxuxefokurinin.pdf
    • http://moreit.ch/productinfo/file/87899854902.pdf
    • http://sportgalaktik.sk/userfiles/file/71339730397.pdf
    • http://austintownfitch1980.com/clients/879833/File/tokenujedunixixamoduzeze.pdf
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/6515b44e1eb7d6cbaa26ccd3bb86b972/xadiretijoragujoje.pdf
    • http://sanarina.de/ckfinder/userfiles/files/sulapad.pdf
    • http://www.supercarrentalsofmiami.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fcd2d02983---jonakitepukopupoz.pdf
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb86a95b4a7---sevugi.pdf
    • http://15fratrowreunion.com/clients/2/2b/2b18ccadde375fd95e9ac2d5db5aaa67/File/xomoxotifalaramuze.pdf
    • https://cavalier-hundezucht.ch/userfiles/file/79870151692.pdf
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608714d6d8c51---besejom.pdf
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/87386688428.pdf
    • https://www.digitalsofts.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce706f716df---fotafaxemoz.pdf
    • http://extintoresorigen.com/images/editor/bubajizafe.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00015a87.bin
19550f62fe492c328f4d0b2438500bfe1699744a9d8917cf86e099367cc04879
pdf-font-stream PDF embedded font (sfnt) at offset 0x15A87 10924 bytes
font_01_sfnt_off00017380.bin
462a4783e98b38620ac8f8ecdcd5a68537a1a8a2bd0fe099007260b825b6a7dd
pdf-font-stream PDF embedded font (sfnt) at offset 0x17380 16196 bytes
font_02_sfnt_off00018903.bin
d8846ca897de48a9edb0c3b83feff3d3ce2273d1f4e65f0de64f99c7e152a325
pdf-font-stream PDF embedded font (sfnt) at offset 0x18903 21560 bytes
font_03_sfnt_off0001c3a3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1C3A3 16792 bytes