Malicious PDF — malware analysis report

Static analysis result for SHA-256 50b661c3752de8d8…

MALICIOUS

PDF

76.7 KB Created: 2021-08-22 11:03:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4adf199f080c3e8d805a481f1d624abf SHA-1: 708eca2d0a820d2aec7a00ce2214458183cdf9b1 SHA-256: 50b661c3752de8d821cf0fd8d82dcef052b83fff37b4af4cdc51c35a53d0142e
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV detecting it as a phishing trojan. The file functions as a link farm, containing numerous URLs that point to compromised websites, suggesting an intent to redirect users to malicious content or phishing pages. The presence of multiple external URIs and link farm indicators strongly supports a phishing or malware distribution attack pattern.

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 https://crewmak.ru/uplcv?utm_term=instalar+piso+laminado+video PDF link annotation
    • http://sillajen.com/fckeditor/_upload/file/xofofezezudis.pdfIn PDF document text
    • http://probeg2000.ru/files/userfiles/files/65493801267.pdfIn PDF document text
    • http://gtlmarinefuel.com/userfiles/file/60288351388.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/651f96857a676ab60cfd499f4af7bc2d/93143335090.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/c89ba2ce4fbf1416b91e79b7091cfcbd/29256628488.pdfIn PDF document text
    • http://vrieshorst.nl/images/uploads/file/kisavuzadiwatula.pdfIn PDF document text
    • http://iwort.de/userfiles/file/sogukuj.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/26018389673.pdfIn PDF document text
    • http://www.europesolidaire.eu/userfiles/files/dapakumex.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1609c9b0ea608c---92510473598.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609116c1e463c---25750591945.pdfIn PDF document text
    • http://atomiccm.com/userfiles/files/gakifun.pdfIn PDF document text
    • http://prefinancovaniehypoteky.sk/res/file/24506540138.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160aa35b036979---36819521095.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/ce524b9aac89de14b6ab5b0d6234cf47/37403517067.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/1606cde367d8cc---56971750749.pdfIn PDF document text
    • https://summit-christian-academy.com/scauserfiles/files/5978861599.pdfIn PDF document text
    • http://cateringkieuan.com/uploads/userfiles/file/meratefowozesedi.pdfIn PDF document text
    • https://napraforgohotel.hu/upload/file/39680155642.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/emg4p4ide7maf5ocrgaem4bd70/6716890937.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_off0000cd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e58d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE58D 15828 bytes
SHA-256: ad833b8060ec2c33275bb369ba554634d94e61dcb2d32f95ede17cc643e395cf
font_02_sfnt_off00010d0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D0E 10572 bytes
SHA-256: cbca02212e2544862d0d72b15454f1f7b104e1bafb4749dc83edaeac4b107e43