Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4458da3cb902bb2…

MALICIOUS

PDF

83.2 KB Created: 2021-09-08 11:28:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4942402a24c1153e311c2866d9751686 SHA-1: 49a48847e3c23b668ea8dd60801216911cd9b43f SHA-256: a4458da3cb902bb23fe5fd1ec77a9b444529e93dea7a74dd3737b889020280f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links to external resources, many of which point to compromised WordPress sites and potentially malicious PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO poisoning campaigns. The document body is heavily obfuscated and does not provide clear instructions, but the heuristics and URL analysis confirm a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/b7pjqcqi2v7v5q4vroi9he5vv6/xinupalotegivomadabuto.pdf
    • https://at-studio.tw/app/webroot/userfiles/files/20210802_113457.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/cce3712d5673b2b40ec42d28d036579e/zapokogiguwobura.pdf
    • http://gandolfiarchitetti.com/userfiles/files/ralisewosagowufojegufab.pdf
    • http://aceonlinementors.com/userfiles/file/45814594487.pdf
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c2ad905892---33354232084.pdf
    • https://lemanssrl.it/file/dujomidosagisut.pdf
    • http://nuovartea.eu/userfiles/files/degatodotoboni.pdf
    • https://torbay.ru/images/uploads/file/boguxakobizaludikebeb.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160c8fae26ba49---bilekalugusaz.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/5b593bf9b892f75752bfdb4e66a4fc6e/94499842843.pdf
    • http://riskhedgetech.com/uploaded/file/63262297461119dfd1a0a5.pdf
    • http://pascalparrot.com/uploads/assets/file/duxano.pdf
    • http://614move.com/clients/4890/File/wibugonugebusarabuzujamuw.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160729b778fa3b---wagogu.pdf
    • http://houselandia.ru/files/zapev.pdf
    • http://www.plan.msu.ac.th/ckfinder/userfiles/files/zozurixosuve.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5f532a365---xavewolomepuxidaret.pdf
    • http://bfr-bialapodlaska.pl/userfiles/file/resumakususalosuzelene.pdf
    • http://studioriboldi.eu/userfiles/files/juravuvajugonetemifudonub.pdf
    • https://cottonweb.net/userfiles/file/4228537199.pdf
    • https://tenfci.org/userfiles/file/serevoxolarigofozakare.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=finite+element+analysis+solidworks+tutorial+pdf
    • http://irodori.kir.jp/files/file/75149499514.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_off0000de68.bin
f12169f52bc3300650d794dcb704d90a663f9577065ec0cd2704b62c65a3fddf
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE68 18004 bytes
font_01_sfnt_off00010cd8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CD8 16792 bytes
font_02_sfnt_off000124ef.bin
931f642715bc3fb6b977ef191f81f21926166e5bf633d97be2592d18bf71da96
pdf-font-stream PDF embedded font (sfnt) at offset 0x124EF 11028 bytes