Malicious PDF — malware analysis report

Static analysis result for SHA-256 31dc34e76a825a94…

MALICIOUS

PDF

91.0 KB Created: 2021-06-28 23:42:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f700abb1eb242c27d62cab14bddb982 SHA-1: 653f0fbcb13e20a011d8772b4c724a3dc39353b6 SHA-256: 31dc34e76a825a94d77780a5a923af9df65814d3e0249accf4600afbb1ec26c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting. These links likely serve as redirects to malicious content or phishing pages, aiming to deceive users into downloading malware or divulging sensitive information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=masculinity+and+meat
    • https://contactfm.be/userfiles/files/7046184323.pdf
    • http://digimaap.com/wp-content/plugins/super-forms/uploads/php/files/8fucsqb54o4avdj4v23ltqabrp/10970951684.pdf
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/7c5b63e1340dccdc3f5db030909896be/52474547928.pdf
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608fa80589f8e---lipafunama.pdf
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/mc6mvkts2rub4kqk93057b4d6p/pedutisapaxu.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a5871aa7485---gonorodomevobaxumoxoribu.pdf
    • http://xn--80aafkqcanfpgnhbng3b5i9a.xn--p1ai/pict/file/vodepowatumarasefozukilux.pdf
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/a2a4710d968c6af6a94b8c31204dc4de/92347412924.pdf
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/3d457e602af0a885292134a5932a59d6/86619603307.pdf
    • http://sy-smile.com/upload/files/zefaji.pdf
    • http://ac-kenigsberg.ru/files/file/paxabowinadan.pdf
    • https://olympicwroclaw.pl/zdjecia/fck/file/tazedexaromurozut.pdf
    • http://slsnn.ru/content/file/lenakenawaveg.pdf
    • http://mognational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b4a09e7a79---podudasubanimumakosepol.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609473520ab02---72609931851.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160939b3d54d93---jupajevetifod.pdf
    • http://cukierniabrzezinski.pl/www/artizam/fck/file/70350466727.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/c9a41d66bd6152bb034ae82bdb4ccd3d/potoniretunolenijugumo.pdf
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/160727e880c14d---segewow.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160838991e835a---760147637.pdf
    • http://perilatomsk.ru/ckfinder/userfiles/files/73869537690.pdf
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a8c1ae96638---12304992804.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160cd3672bf123---17613191771.pdf
    • http://bhk-aindling.com/userfiles/files/84953108565.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_off00010086.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10086 16792 bytes
font_01_sfnt_off0001189d.bin
faf1d05a595a1475dc1f23fcdd60dcc23a47fa0be0c0229197f11fa11c618f48
pdf-font-stream PDF embedded font (sfnt) at offset 0x1189D 10516 bytes
font_02_sfnt_off0001308e.bin
c25979886d6e6a476faba0f9fbf60750ca6179ed4637c6e5a4ac7565dfbf66de
pdf-font-stream PDF embedded font (sfnt) at offset 0x1308E 17692 bytes