Malicious PDF — malware analysis report

Static analysis result for SHA-256 51643a9fe2b7285e…

MALICIOUS

PDF

69.4 KB Created: 2021-09-02 08:57:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b28f9b87216d096fdee5ccc207982efc SHA-1: 634a9f4782dd21d71636eac20e2d4afafd44a260 SHA-256: 51643a9fe2b7285e2c9e299755cc2f75b6263c48beb9fe0e1623c8e47a94953e
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised CMS upload storage and disposable hosting domains. These links likely serve to redirect users to malicious sites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://cinebuzz.be/uploads/userfiles/files/wazonadaluxepiweludejavu.pdf In PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/95edb0d4d11f98aaade89f0118a5deb5/jakivepebipowimaxelub.pdfIn PDF document text
    • http://fly.no1-yes.com/userfiles/file/68716688399.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///tukusuropavize.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/66a27a7e7232d966a5dc9347e97aaf92/nebejozaxuwibefixow.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077965162dda---sogofogamupuwegilaloriku.pdfIn PDF document text
    • http://fitviewer.info/files/file/27474739311.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/ecfc46541ad4f565d89879ac89346d92/34888259689.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210806215112.pdfIn PDF document text
    • http://bsbcarpet.com/userfiles/file/42531498365.pdfIn PDF document text
    • http://quiltingacademy.info/fckeditor/userfiles/file/24370717377.pdfIn PDF document text
    • http://evpltravel.com/xv_image/file/xizikatofonepalale.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1612b54db3dbfd---gawonagugagodiwi.pdfIn PDF document text
    • https://www.endthestigmacounselling.com/wp-content/plugins/super-forms/uploads/php/files/hmop2fbjo02s8et45memq43e9k/filifuku.pdfIn PDF document text
    • https://rosycaffe.com/file/fojagilolasavirepomon.pdfIn PDF document text
    • https://maintogelonline2.org/contents//files/pokivomufajipanodew.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612dae806c9ba---libin.pdfIn PDF document text
    • http://gazomotor.com/allinone/file/58061703020.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+get+an+ender+eyePDF link annotation
    • 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_off0000b3be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3BE 10308 bytes
SHA-256: ba2fdb85c4aaa0807085a65c98a912f0ae429c539af73302ee286c567c00dd31
font_01_sfnt_off0000cae3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAE3 14904 bytes
SHA-256: e6d23f9e16823b57f7fe9027930bc75b59c1f3ef09f8e9d789cad9e024ff22e8
font_02_sfnt_off0000efdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFDD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1