Malicious PDF — malware analysis report

Static analysis result for SHA-256 477607fe71666216…

MALICIOUS

PDF

70.7 KB Created: 2021-09-26 18:33:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: ae3d03585123d3d2878c0fbc4df290db SHA-1: a89ed5178bc4d4c25fcf15fbffbccabaa2f0ebdc SHA-256: 477607fe716662162ceb49096c6a64f5a508554a8d4efdd9cd6ff92f9cacf5ae
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as 'Pdf.Phishing.Trojan' and a machine learning classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to compromised WordPress uploads and disposable hosting, with numerous embedded URLs designed to redirect users. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://queure.ru/uplcv?utm_term=transfer+photos+to+new+phone PDF link annotation
    • http://tmtechvn.com/webroot/img/files/welazijaxakakolekujid.pdfIn PDF document text
    • http://sanfrancescovet.com/userfiles/files/33244249528.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/busepini.pdfIn PDF document text
    • https://andana.us/files/files/98959359118.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/nimudipesaridewewipiz.pdfIn PDF document text
    • http://nattuvaartha.com/assets/ckfinder/core/connector/php/uploads/files/75260264638.pdfIn PDF document text
    • https://equator-maritime.com/userfiles/file/810946084.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/0a57fdab5bfe85378e6679f0452c5727/kerisolasefebomus.pdfIn PDF document text
    • http://stepasidemedical.ie/images/uploads/file/72912863052.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f1b727b1a3---49890066644.pdfIn PDF document text
    • https://motoralbini.it/files/file/49524036164.pdfIn PDF document text
    • https://sma-dfgg.org/site/admin/file/koruzulaluloxek.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/51829365165.pdfIn PDF document text
    • http://www.astmalek.cz/obrazky/file/wafuxaxoviwatiku.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16138ff8b94dec---fefukot.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/fb961ea1c25b4caf03d910744aa41ded/wowibuzugegaromugevepe.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/16144bb8ee4910---28459915713.pdfIn PDF document text
    • https://fibaquitaine.fr/cebatrama/userfiles/files/89706232760.pdfIn PDF document text
    • https://inprovitparaguay.com/ckfinder/userfiles/files/24902713269.pdfIn PDF document text
    • http://changwontour.kr/FileData/ckfinder/files/20210907_AC0AC61311DFF663.pdfIn PDF document text
    • https://absoluteanytime.com/media_file/files/files/72632389366.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/ditixajo.pdfIn PDF document text
    • http://corse.annuaire-regional.com/ckfinder/userfiles/files/18092007607.pdfIn PDF document text
    • http://thietkewebbacninh.com/webroot/img/files/gupabijafukaxosa.pdfIn PDF document text
    • https://digireg.cz/upload/mejunetisaku.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b4aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB4AA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ccc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCC1 10368 bytes
SHA-256: 5630d40d1b451a729ede2bac5025ef0276e491638d1ecfe837e6f97887afaafb
font_02_sfnt_off0000e434.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE434 15396 bytes
SHA-256: ac3c948d5c815edd6edb3526335ac58a08eadb025bbd69d09b585f6d9ba8854f