Malicious PDF — malware analysis report

Static analysis result for SHA-256 a407a4a7a6270cd3…

MALICIOUS

PDF

74.1 KB Created: 2021-09-02 10:34:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b5f94e222d28431d2547899b610b0c9c SHA-1: eda65a4f5c61b5c81153994b9e9d417a16be41f1 SHA-256: a407a4a7a6270cd3df8a129d18131e9c8b54b5ce709b708f8346f031fd78d7b7
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users. The document body is heavily obfuscated and contains metadata indicating it was generated by wkhtmltopdf, not typical user content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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 http://spreewaldatelier.de/img/editor/file/45037225576.pdf
    • http://raiders71.com/clients/4/41/4134020f2f298c111575624a380fabfc/File/wusutabafigatijafoxebex.pdf
    • http://studioego.cz/userfiles/file/73431745290.pdf
    • http://kururlaub-ungarn.de/bilder/files/buwel.pdf
    • http://summitremodelinginc.com/userfiles/files/lisasizamotolunexiz.pdf
    • https://tinnituskozpont.hu/files/75622350056.pdf
    • http://agro-vostok.ru/userfiles/file/55643069911.pdf
    • https://euforbiabulgaria.com/uploads/pages/files/fowibuvizokufijeka.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/160fe85fa22e47---gokowazumafopame.pdf
    • http://anonelectronics.com/admin/fckeditor/editor/filemanager/connectors/php/upload_jpg/file/202108041124545687.pdf
    • http://laconchigliacasevacanze.it/userfiles/files/64547195270.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b00d82cab82---32776850870.pdf
    • http://jarosi.hu/files/file/notatozabasulofowuni.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/ef5dcfdd3b457006494d78f469778137/91311066426.pdf
    • http://seamcc.com/UserFiles/files/84134635210.pdf
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/2a2797542693e1cb9185efae05061e7b/72528187953.pdf
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/ebb2d1a32d530a607c494c69c6534d38/medegudegigevik.pdf
    • http://skiflogistics.ru/userfiles/file/lurebakaguvezulux.pdf
    • http://www.s4b.nl/upload/files/lojexuloza.pdf
    • http://www.maarsehoveniers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b2dae09d0f5---wefusudafakazo.pdf
    • https://orangerun.re/photo/files/pekolimotojugebonudi.pdf
    • https://mvmdigital.gr/files/files/57651584869.pdf
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc373e6c9f0---guvoput.pdf
    • http://e-skala.pl/userfiles/file/80640590757.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=mitochondria+do+not+occur+in
    • 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_off0000c3c3.bin
663440fc32ff0a608bf138945986f8183c4fd54798ab2c2d71c9923cd0cd8041
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3C3 10212 bytes
font_01_sfnt_off0000da94.bin
3222413d4195aafa7eed850d577988026a7c36e2ea3ce128899f7b54e6943751
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA94 15424 bytes
font_02_sfnt_off00010179.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10179 16792 bytes