Malicious PDF — malware analysis report

Static analysis result for SHA-256 288b2e1c46810020…

MALICIOUS

PDF

89.2 KB Created: 2021-09-21 05:36:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: a845f07b0b6cac1d6ae546d918e67ac3 SHA-1: 941c35e1951750975e1718085cd8a11fb609c82a SHA-256: 288b2e1c4681002087c3ecb5452a1975af53df8d24925630643fe7659748e0ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9138

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=funny+m+words PDF link annotation
    • https://ecoquimica.cl/dinamicos/uploads/file/wufule.pdfIn PDF document text
    • https://portalbime.com/UploadedFiles/New/file/18597629450.pdfIn PDF document text
    • http://hzxgdz.com/images/upload/File/97469757109.pdfIn PDF document text
    • https://arendic.cl/files/sevore.pdfIn PDF document text
    • http://dar-tom.pl/userfiles/file/59468573987.pdfIn PDF document text
    • http://www.enfersalus.com/ckfinder/userfiles/files/sarewugimi.pdfIn PDF document text
    • http://elistaprezentow.pl/userfiles/file/robuminabokage.pdfIn PDF document text
    • http://mp-hd.de/data/aktualnosci_imgs/file/8808112936.pdfIn PDF document text
    • http://ukrfirework.com/images/file/pubomik.pdfIn PDF document text
    • http://tochuchoinghi.org/files/pevamuvuparapixopuwav.pdfIn PDF document text
    • http://bonfiremadigan.com/uploads/fckeditor/file/30697539568.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161409b50e91ed---29907787107.pdfIn PDF document text
    • http://cyc.cz/pictures/clanky/files/kijoboxupafaxe.pdfIn PDF document text
    • https://serrechevalier-skifun.com/imagesfile/nowumekagajenibaro.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ecf7f7acf4---pudevejazugotimev.pdfIn PDF document text
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f95f3b5074---3061863032.pdfIn PDF document text
    • http://honghuibio.com/d/files/35834963515.pdfIn PDF document text
    • https://odlingfamily.com/userfiles/file/34440780084.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/bfcc16008302f1f4dc2ce92a5328c7de/ridipadefiruravapinujem.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16139bbae340e7---rogejizibelanekowov.pdfIn PDF document text
    • https://viadagio.be/userfiles/file/vitilobojo.pdfIn PDF document text
    • http://zespolbahamas.pl/zdjecia/file/wakudijotutafufirum.pdfIn PDF document text
    • https://ecowaytechnologies.com/ckfinder/userfiles/files/jijipaxobu.pdfIn PDF document text
    • http://greenld.com/userfiles/42794799545.pdfIn 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_off0000ff71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF71 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11783 18420 bytes
SHA-256: 7dd41bd6e86c9a5e474f4a28a5986b9aac959612c5d5f40a662039b67eb6a390
font_02_sfnt_off000147f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147F3 10156 bytes
SHA-256: ea36cac948b03d6c08cb145a04759b4b758c7d7dce5f136b3faf0e211f748d12