Malicious PDF — malware analysis report

Static analysis result for SHA-256 0f494728eab7f380…

MALICIOUS

PDF

85.1 KB Created: 2021-09-18 13:15:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e26c066d1faea18145cf004e2cca28e7 SHA-1: d43649c3ad0e521792a6d5ff9cb823a628567b38 SHA-256: 0f494728eab7f380a34a08489859258b2311a3cdd2804d76a48219f5aacbb298
156 Risk Score

Malware Insights

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

The PDF 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 many URLs pointing to compromised CMS upload directories or disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://abwingsjanaf.com/uploads/files/22684521656.pdf In PDF document text
    • https://penmypoem.com/new/admin/uploadfiles/file/78805737582.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/mosojesujogetabagew.pdfIn PDF document text
    • http://uptindia.com/newsimages/file///nixijurokakonomenuridatiz.pdfIn PDF document text
    • http://willajarmar.pl/userfiles/file/jazorot.pdfIn PDF document text
    • https://baoholaodong24.baohohoanglong.com/userfiles/file/linitolufevij.pdfIn PDF document text
    • http://a2kat.ru/userfiles/file/lopogujepaz.pdfIn PDF document text
    • http://szjg.hu/images/file/12385433175.pdfIn PDF document text
    • https://mariapolis.es/ckfinder/userfiles/files/natomufex.pdfIn PDF document text
    • http://fabiocaronearchitetto.com/userfiles/files/1332333185.pdfIn PDF document text
    • http://yejida.com/userfiles/file/21952061465.pdfIn PDF document text
    • http://cee1968.com/ckfinder/userfiles/files/vawedavugokugisele.pdfIn PDF document text
    • http://jorkurojus.com/userfiles/file/jojevusapebinivexavema.pdfIn PDF document text
    • https://silverlabpupsforsale.com/userfiles/files/gidebijevodug.pdfIn PDF document text
    • http://myucpb.com/userfiles/file/segadepagolanipak.pdfIn PDF document text
    • http://provia-events.de/pics/fotos/1/file/54341306453.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/9c6cd48674b7cf27f04a892ad256911d/kutomidevukuxatir.pdfIn PDF document text
    • http://aktifbant.com/resimler/files/nipofijiniw.pdfIn PDF document text
    • http://www.communityheroesproject.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613f86391a570---99499420894.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16142a9a80be41---bajakaz.pdfIn PDF document text
    • https://petikdaun.com/contents/files/60523812099.pdfIn PDF document text
    • http://nomorecpapmachine.com/userfiles/files/57462134230.pdfIn PDF document text
    • http://a1climbing.com/userfiles/files/manuroderagagud.pdfIn PDF document text
    • http://oris-am.com/editor_up/kuvolunoxulaluzinewori.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=developing+android+apps+in+pythonPDF 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_off0000e574.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE574 10852 bytes
SHA-256: 4544c59126f8e3c282318f019ca4bf9ae9cce17a2043f69839bf21257f94ed0e
font_01_sfnt_off0000fe49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001165b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1165B 18672 bytes
SHA-256: f4f1cb2905964abc5ae9b992a71e60d241b87b07942649fbbe4d7e035da8803e