Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ff793609581028…

MALICIOUS

PDF

73.8 KB Created: 2021-06-29 01:27:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f9e43e54fc74f652d220bcbbdf1006f7 SHA-1: edae60de6755fc76a802cc8f6ab2622bc2025cca SHA-256: a4ff793609581028f1f0d982a10e362aa454f7de1b1ef6031611abe4f98ea064
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics point towards the document being used to redirect users to malicious sites for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://medvor.ru/uplcv?utm_term=4+letter+word+with+swing
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/le2epa0h790fghgeijaao3nm88/wuwafivegisegomet.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3623c35a85---38171747882.pdf
    • http://acpiindia.com/userfiles/file/55659158292.pdf
    • https://aronabritcan.com/userfiles/file/baxabekak.pdf
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/21duk263uc9no6istkvjltd3q5/xofozodogaxedenixusalazu.pdf
    • http://alpha-th.com/userfiles/file/wonunutijepu.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070e7164eaf4---gawasakafozobirasejob.pdf
    • http://albatrossmrn.com/konadnew/userfiles/file/norolafa.pdf
    • http://computerdoki.hu/user/file/pofiturijawite.pdf
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8f86d67047---xitaleg.pdf
    • http://hrt-foto.hu/_user/file/mufuxaxiduwi.pdf
    • http://daglichtfilters.nl/ckfinder/userfiles/files/11631938379.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160acc9ad731d1---kujexo.pdf
    • http://ambvetsanprospero.eu/userfiles/files/fadufuwitu.pdf
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081383be6f75---fonegexamagozuwuda.pdf
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/98b79ef24f75063968b95554705bc460/430956560.pdf
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081eb9529291---59783390622.pdf
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609dde2ad5943---8040114615.pdf
    • http://garderoba.sk/images/_file/95448519129.pdf
    • https://xetnghiemadndanang.com/upload/userfiles/files/sunumeletigajafemi.pdf
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/5eanrb55l1e8hpi0amqi8m3rh5/zukemodepapok.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_off0000c052.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC052 16792 bytes
font_01_sfnt_off0000d864.bin
6697c3fb9132a23c549f4b338f11de1f44c7508c35a3d4c09006de1ce3e7d618
pdf-font-stream PDF embedded font (sfnt) at offset 0xD864 16496 bytes
font_02_sfnt_off00010300.bin
e31e7f9b3aad2ff847a00fa98653cd3e5a844be4779517c8f8f3489d01732b2a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10300 10432 bytes