Malicious PDF — malware analysis report

Static analysis result for SHA-256 678ee5fc744e6ccb…

MALICIOUS

PDF

83.5 KB Created: 2021-09-05 20:09:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: e7f25705aef733adbe7b6e0dda9a957f SHA-1: 7a138fad344ef2d2c25193ab651051bf33953872 SHA-256: 678ee5fc744e6ccb02e70a7cf85fcfb9965049ec322e9692aed1d815d79f4ef7
96 Risk Score

Malware Insights

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

This PDF file was identified as malicious by an ML classifier and exhibits characteristics of a link farm. It contains numerous URLs pointing to other PDF files hosted on various domains, some of which appear to be compromised CMS upload directories. The primary purpose seems to be directing users to external resources, potentially for SEO spam or to distribute further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://explosivedevices.ru/media/file/99529929685.pdf In PDF document text
    • https://thietbivesinhanhhuy.com/asset/files/74824151705.pdfIn PDF document text
    • http://st-communications.com/ckfinder/userfiles/files/29635972685.pdfIn PDF document text
    • http://dalnoboy.net/data/filestorage/upload/files/3979217589.pdfIn PDF document text
    • http://csc0851.com/userfiles/file/20210714024109_9ao3em.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/16089b007f3559---kobuponelazijumu.pdfIn PDF document text
    • http://wcsps.com.tw/ckfinder/userfiles/files/98747469832.pdfIn PDF document text
    • http://wefocusdesign.com/upload/files/24282023912.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161195ff5f1caa---94750838802.pdfIn PDF document text
    • http://myjobcareer.net/userfiles/file/2021062114343173499.pdfIn PDF document text
    • https://prosegik.com/wp-content/plugins/super-forms/uploads/php/files/91d5d7bdccbac691637e02acb2443cc8/86423621441.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/b59383a4014322b4c4ee0f77df9476af/luneti.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/8304490415.pdfIn PDF document text
    • http://es-umzuege-transporte.de/wp-content/plugins/super-forms/uploads/php/files/28b48c5fac5257d2d2b721a64b96b27b/bunozugegutow.pdfIn PDF document text
    • https://prana.video/wp-content/plugins/super-forms/uploads/php/files/a1or8dvd3ji33iro9i3kpcer22/debiwanax.pdfIn PDF document text
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/499730d4f1ed9102ec08d3b0f5c01b17/72947524407.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/3cc74fe39ccf564dd784ef90b49f6050/75304354445.pdfIn PDF document text
    • https://anfauglir.com/images/file/39682591032.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210830005740.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093cbfe2e4db---69789856496.pdfIn PDF document text
    • https://prestinieurope.ch/userfiles/files/memuvef.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607017f0c12f0---nebaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=tata+cara+haji+dan+umrah+pdfPDF 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_off0000dfa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFA9 10612 bytes
SHA-256: dcd63a3de1e4d2357bd19c5bf3e1dce316ecd618a61bada2d7114d3ba6b3a369
font_01_sfnt_off0000f7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A1 18836 bytes
SHA-256: b9c49db4bdd5ef9b3d633ca72b140961642a9dee8407cf953c44397e9b0be053
font_02_sfnt_off000127f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1