Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a4f3af8cba7c0b0…

MALICIOUS

PDF

90.0 KB Created: 2021-09-16 08:03:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 78544fc0ab9c44f05f9ea682766cb73c SHA-1: 9a33542adcb4a3e8e7d0b44acefb0662d86ab053 SHA-256: 1a4f3af8cba7c0b0785d272cf717654e082569b2dc00b2eef901896fce29c560
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs pointing to various domains, many of which are associated with compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the nature of the embedded URLs suggests a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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://irlanc.ru/uplcv?utm_term=apps+to+watch+free+series+and+movies PDF link annotation
    • http://aircond.md/upload_fck/file/duzewujezujakarijenu.pdfIn PDF document text
    • https://riwg.in/userfiles/file/tojakamulenaj.pdfIn PDF document text
    • http://sakurahoaanhdao.com/webroot/img/files/9177609200.pdfIn PDF document text
    • http://krukaiart.com/userfiles/files/rejewafaxanurabigoxi.pdfIn PDF document text
    • http://aburobocon2019.mnb.mn/uploads/files/74404378246.pdfIn PDF document text
    • http://santeh.md/img/files/tokirogagenajibu.pdfIn PDF document text
    • http://allgeology.ru/ckfinder/userfiles/files/60700517053.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/63288995098.pdfIn PDF document text
    • https://mama-light.net/business_school/uploads/file/gejumelenosenewo.pdfIn PDF document text
    • https://ku4ysk-9lgp4y.com/contents/files/29666477293.pdfIn PDF document text
    • https://swagath.co/new/ckfinder/userfiles/files/92490602011.pdfIn PDF document text
    • https://gancza-yacht.pl/userfiles/file/69077613749.pdfIn PDF document text
    • http://studioferrato.it/userfiles/files/masigex.pdfIn PDF document text
    • https://webmenuplus.com/images/file/rupajesunenikibowite.pdfIn PDF document text
    • http://pokemom2.com/uploads/files/82483862299.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613cc30740e88---digotanazul.pdfIn PDF document text
    • https://djecijagarderoba.me/userfiles/file/jevixirotu.pdfIn PDF document text
    • http://homeopathyhongkong.org/files/53095161274.pdfIn PDF document text
    • http://stmrcstvm.com/userfiles/file/kupovexeriguvamugukava.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/eea05532748ab6858d5c59fb3f5764e7/pukarituzozovenonad.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/natowuruxi.pdfIn PDF document text
    • http://trainternational.in/wp-content/plugins/formcraft/file-upload/server/content/files/16136db2c48b4d---dodirur.pdfIn PDF document text
    • http://preiswerte-unterkunft-papenburg.de/mediapool/63191807684.pdfIn PDF document text
    • http://bayanairag.com/uploads/userfiles/files/fowijevuvogezedofifanomis.pdfIn PDF document text
    • http://bharatdarshan.net/rgroup/ckfinder/userfiles/files/5618626884.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_off0000fb00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB00 10972 bytes
SHA-256: a318cad89d68211380819a94a18d0493973f55073bc58a9654ba8f82caa2f3c8
font_01_sfnt_off00011468.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11468 17724 bytes
SHA-256: 483a51f137577debba333103e8a86b475930c39ef606046042e199ce3bbb5737
font_02_sfnt_off000141d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1