Malicious PDF — malware analysis report

Static analysis result for SHA-256 51108d4ffdfee7c9…

MALICIOUS

PDF

75.4 KB Created: 2021-09-21 09:19:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 28980e2cc62e18b38530edc42fa50189 SHA-1: a9c52cc1407e13b0171a86fb6e44cf76d68e8273 SHA-256: 51108d4ffdfee7c9f8a4541574c5f26cdba23e7e9791aa48f5eeaa9bce7592cb
184 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 an embedded JavaScript stream and numerous URLs, many of which point to compromised websites or are part of a link farm designed to redirect users. The presence of JavaScript suggests an attempt to execute code, likely to download further payloads or facilitate phishing. The heuristic 'SE_CALLBACK_LURE' also indicates a potential callback phishing or tech-support scam pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=android+phone+battery+life+chart PDF link annotation
    • http://studioarchoggianiepartners.it/userfiles/files/45285059993.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614163c37388b---51985054544.pdfIn PDF document text
    • http://dayuntang.com/assets/uploads/ckedit/files/20210916015446.pdfIn PDF document text
    • http://lejonhund.com/upload/57253718713.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141117f0a8a8---72166356516.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/69730098239.pdfIn PDF document text
    • http://masterkontroll.hu/ckfinder/userfiles/files/33097818257.pdfIn PDF document text
    • https://owop.challengersports.com/userfiles/files/63959531961.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/75991408e59462e85cd371d37e075c2b/rapukogasuze.pdfIn PDF document text
    • http://anchor-m.com/js/upload/files/simubiluguxukivofirerumo.pdfIn PDF document text
    • http://tpdw.pl/userfiles/file/jajewimulom.pdfIn PDF document text
    • http://cachnhietwin.com/luutru/files/nofolusepukopefanaja.pdfIn PDF document text
    • http://bluecars.pl/userfiles/file/69200715798.pdfIn PDF document text
    • http://24x7taazasamachar.com/assets/ckfinder/core/connector/php/uploads/files/ximakoxujavinebuku.pdfIn PDF document text
    • http://geoass.eu/userfiles/files/23409836311.pdfIn PDF document text
    • http://ergakiland.ru/files/files/lajaserotigijeboxawe.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/88374731099.pdfIn PDF document text
    • https://trvstore.com/userfiles/file/33177428449.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/483c9141ae9445c007cf6f01e7695e0c/fopowiv.pdfIn PDF document text
    • http://kwiatmetal.pl/userfiles/file/24166578044.pdfIn PDF document text
    • http://citlak.de/admin/UserFiles/file/32049284079.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_off0000c243.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC243 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000da55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA55 17284 bytes
SHA-256: 82ed2ea8eb881b16f95bb2880e6076dd86ce18e9592463f7945ab159e3776f1d
font_02_sfnt_off0001075e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1075E 10784 bytes
SHA-256: 8bbd472b70c1f2940e9de5b676d5a71a7181586ef1dc91b4c8cd1d412c88351c

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