Malicious PDF — malware analysis report

Static analysis result for SHA-256 b551c2874384ac47…

MALICIOUS

PDF

79.5 KB Created: 2021-09-30 20:00:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 737bb977816c16e378958488b914efd5 SHA-1: fe799102e73f32c83afdc05698706a2351747eb5 SHA-256: b551c2874384ac4711ffa637ba78473ce33cff5bd49c771227500b5ebcb61248
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The presence of compromised CMS upload links further supports the malicious nature, likely serving as a distribution point for further payloads or phishing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://nomylo.ru/uplcv?utm_term=parmak+izi+kilidi+android PDF link annotation
    • http://simoncaulkin.com/images/gevusajodexipiwasog.pdfIn PDF document text
    • https://bimetoor.com/basefile/bimetoorir/files/jesumufidisi.pdfIn PDF document text
    • http://tallygroupkwt.com/uploads/file/11932064308.pdfIn PDF document text
    • https://stauber.lt/images/files/68803583519.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161542a0351e1d---ligujaxobu.pdfIn PDF document text
    • http://bjjiffy.com/upload/51186722935.pdfIn PDF document text
    • http://zlhk.ru/upload_picture/file/tidurinarogip.pdfIn PDF document text
    • http://dralituncer.com/userfiles/file/22904764931.pdfIn PDF document text
    • https://stayinbranson.com/ckfinder/triplebuserfiles/file/lizoxotivid.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/dovumekukaberukidufo.pdfIn PDF document text
    • http://madiagranitosilano.it/userfiles/files/gefetozukuwokafin.pdfIn PDF document text
    • https://abofahed.com/userfiles/file/bozerilikejalugina.pdfIn PDF document text
    • http://csc-0898.com/userfiles/file/20210912070231_2w7c7e.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/ucvof4rttplg4akju7iodjs3sp/50113708941.pdfIn PDF document text
    • http://di-tech.kr/fckeditor/userfiles/file/34611288572.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/70522489878.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/53552082694.pdfIn PDF document text
    • http://beming.com/ressource/site-image/files/zopovotirumawojosifa.pdfIn PDF document text
    • https://northcoteplaza.com/userfiles/file/42111294695.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/0adeb6d301dce6235cbb6d93815abfa0/24425157096.pdfIn PDF document text
    • http://rdmsrl.it/userfiles/files/31088369257.pdfIn PDF document text
    • http://icsbc.ru/fuploader/file/88744084959.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_off0000d334.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD334 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000eb4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4B 10164 bytes
SHA-256: f2be1b9819e59565065da95097be91c8bdbe319eab5b7b2f76ebe7dd27d782d5
font_02_sfnt_off000101e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101E8 18064 bytes
SHA-256: 3ea94bde7c03450351db485c797c507e640ede964c369a55cc7be4017f907ac8