Malicious PDF — malware analysis report

Static analysis result for SHA-256 a555bdaebf3f7b70…

MALICIOUS

PDF

114.6 KB Created: 2021-07-14 03:46:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1e4639166e8b96280ac7e1cdd756d2a5 SHA-1: 64de7cba4148ab39be2a052bdae50e1b10f245f9 SHA-256: a555bdaebf3f7b70758e6a699d7475b1806271959b96870809773d8318561930
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links to external websites, many hosted on compromised or disposable domains, suggesting a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics (compromised CMS upload link farm, SEO disposable link farm) strongly suggest this document is designed to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://chcial.ru/uplcv?utm_term=the+difference+engine+developed+by+charles+babbage+was+driven+by
    • http://weddingdiy.cc/uploadfiles/files/20210613_025243_3739.pdf
    • https://www.justgym.co.za/wp-content/plugins/super-forms/uploads/php/files/c3fksj7aukop0187csf993ovqj/batizagozelugoded.pdf
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ba3cf87960---81496297791.pdf
    • https://fullmagicweekend.com/ckfinder/userfiles/files/sizid.pdf
    • http://mdbim.pl/ubezpiecz/obrazy/file/37024176785.pdf
    • http://clearlakesd.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a4ad3178f04---59848584348.pdf
    • http://www.molinoag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0a012ad090---vupugigorov.pdf
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608dcdee605af---benefabemim.pdf
    • http://memphiscentral1969.com/clients/865565/File/dufuxipugakujaki.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cf2dd1bcc6f---rizuzuxonexosudemim.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160a24b1663566---gafafipizul.pdf
    • https://law.myvzl.com/wp-content/plugins/super-forms/uploads/php/files/e0g31u0am6db7busagud199s3g/dafopig.pdf
    • https://www.loscam.com/lib_common/ckeditor/ckfinder/userfiles/files/95048106134.pdf
    • http://rulada.by/upload/editor/files/wobefagupus.pdf
    • http://28777886.com/Lpf/UPFILE/userfiles/files/29214101402.pdf
    • https://immo-cjeanpaul.lu/userfiles/files/55211109357.pdf
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c186ee2f6be---76684690689.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/8329884ddff8511adff2cc94261716f0/mumipixufuwukanojolemubo.pdf
    • http://micronforgacsolo.hu/UserFiles/file/loparifajoramugupegikukig.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608a9878b1069---77186636764.pdf
    • http://cityfate.com/files/files/13459256495.pdf
    • http://melinterior.ru/userfiles/files/77235326529.pdf
    • https://sf-tfi-pgu.uz/wp-content/plugins/super-forms/uploads/php/files/5719352d585af8dd2e1c8f269badd569/60396629992.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_off000159b2.bin
dcceee41f06ff325ef92c81545802aaecc02cec1902367ff0df503f549571834
pdf-font-stream PDF embedded font (sfnt) at offset 0x159B2 19204 bytes
font_01_sfnt_off00018a9e.bin
b76d5450228262c5f8aa52fbf692b12948c56dc854b59f26ad1278493c5116fd
pdf-font-stream PDF embedded font (sfnt) at offset 0x18A9E 11168 bytes
font_02_sfnt_off0001a441.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1A441 16792 bytes