Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6899160845bdabf…

MALICIOUS

PDF

85.5 KB Created: 2021-09-20 08:21:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 5b823a2140fcf209a44370d621f1200b SHA-1: 1d916ae90e597c2d118a8876a99d369633e1cb1d SHA-256: a6899160845bdabfdc276d6574982ea6930840c43cf7f85a0598b115c5ad4c8b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to disposable hosting or compromised CMS uploads. This suggests the document's primary purpose is to redirect users to potentially harmful websites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://suacuachuyennghiep.com/uploads/files/41980017351.pdf In PDF document text
    • https://officialbacknumber.org/editor_up/21099534722.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/84188099081.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/161312e77c8472---sumupefewu.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/96fe08ba59fad4a733ffcbf7efe403dc/rikij.pdfIn PDF document text
    • http://medi-sen.com/files/files/10559170128.pdfIn PDF document text
    • http://irinka.org/ckfinder/userfiles/files/4352622826.pdfIn PDF document text
    • http://roseeskin.com/userfiles/file/20210920114454.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/d5a0n3e49vkto5buo1hpp3sljo/sigebofunisorebeki.pdfIn PDF document text
    • http://tjsyjdq.com/v15/Upload/file/202192919518937.pdfIn PDF document text
    • http://naszymsladem.pl/upload/file/pibipinis.pdfIn PDF document text
    • https://superpackeg.com/userfiles/file/40675861009.pdfIn PDF document text
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/3adcc3bcd05d3c3838c567c93fb5553b/75473991572.pdfIn PDF document text
    • https://xn--psg-9lac.hu/files/files/51653732109.pdfIn PDF document text
    • http://jnnycc.org/userfiles/file/kosasiwo.pdfIn PDF document text
    • http://sumisaedu.com/FileData/ckfinder/files/20210919_35BAB8A3747526EE.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1612f3d97d753c---9264624352.pdfIn PDF document text
    • http://savytrading.com/userfiles/file/9277548872.pdfIn PDF document text
    • http://sbairs.com/datas/files/nufasopilinaguzikib.pdfIn PDF document text
    • http://autowagon.it/userfiles/files/3130935267.pdfIn PDF document text
    • http://globalcenterhotels.com/bot/ckfinder/uf/files/62075721419.pdfIn PDF document text
    • http://gibisch.biz/files/files/93740229622.pdfIn PDF document text
    • https://birsamundapark.in/userfiles/files/xubakuxuwixaropiguri.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=smart+app+androidPDF 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_off0000ecfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECFE 10284 bytes
SHA-256: 79b4c51b06d916bcaf2abeadcbcd327dc2620caef200a60c7e527122e2b7bef3
font_01_sfnt_off00010406.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10406 17216 bytes
SHA-256: 5c11e04703bd201c6e06f62800b1134bf5f59dcaf0e3b838320d8f638c8cc62b
font_02_sfnt_off0001307a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1307A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1