Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b34b0f85b4fb4f…

MALICIOUS

PDF

72.8 KB Created: 2021-09-04 02:02:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 587d3280142d17bb555f0f3993848883 SHA-1: 398c5f1901fbd601c3a0ed9c354cf0af48b62e5c SHA-256: 83b34b0f85b4fb4ff69fdc17670f32745e05c093c05669693c2fabb04ed10029
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs that are part of link farms, many hosted on compromised CMS upload directories, suggesting an attempt to obscure the final malicious destination. The presence of these link farms and the overall structure indicate a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://oniceh.ru/uplcv?utm_term=small+size+pdf+compress PDF link annotation
    • http://thuduchouse.vn/pics/file/mapumepuwanex.pdfIn PDF document text
    • http://kayamedbursa.com/userfiles/file/48403999587.pdfIn PDF document text
    • https://globalclassic.org/wp-content/plugins/super-forms/uploads/php/files/qf70bijcj26bv7v0iqqiuis6df/wered.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a46af4e484c---30775794482.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/3u95nrilan7r89jfpc4oeall6l/61893818282.pdfIn PDF document text
    • https://sealskinz.ru/files/file/kadipin.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f280f9c1d5---baboluz.pdfIn PDF document text
    • https://tezerwatch.com/file/upload/files/07-25-09-34-53-44.pdfIn PDF document text
    • http://thedigitalscorecard.com/userfiles/files/56768918733.pdfIn PDF document text
    • http://med-os.com/user_upload/file/witedoba.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f5e5a785e37---94080532998.pdfIn PDF document text
    • https://aodaixuan.vn/app/webroot/upload/image/files/504083315.pdfIn PDF document text
    • http://norview63.com/clients/5/59/59ba6e1aa7224642a1eeb14435756cbf/File/79049079060.pdfIn PDF document text
    • http://nanouklid.cz/upload/file/mepokuvotowi.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1a27691b53---timijigenoxajede.pdfIn PDF document text
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/mob2avkl3l68u1p0peh9dc1c76/46994008512.pdfIn PDF document text
    • https://atamergranit.com/userfiles/file/86271579980.pdfIn PDF document text
    • http://statsale.com/data/upload/ck/files/sozulovov.pdfIn PDF document text
    • http://flexa.cz/docs/file/jivanujopufejobe.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/1db1ca490a2b6427fa44786b43457081/feboritujuzovilizi.pdfIn PDF document text
    • https://subarini.ro/mm/file/gudajadi.pdfIn PDF document text
    • http://kiszelyugyvediiroda.hu/docs/file/taliginib.pdfIn PDF document text
    • http://allivecoat.com/userData/board/file/2604948338.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_off0000bcd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCD9 10716 bytes
SHA-256: b88ac80e27a2315ac20a842b157bee07777603d97d41be0444ecf7df5e1138ff
font_01_sfnt_off0000d568.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD568 15604 bytes
SHA-256: a5b1d4a55ea19444396de4fdb60fe56114d712b006ee91920f8bd146e90e9082
font_02_sfnt_off0000fd4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD4B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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