Malicious PDF — malware analysis report

Static analysis result for SHA-256 1881509cef7502b1…

MALICIOUS

PDF

81.0 KB Created: 2021-09-09 10:38:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 7ef41535245ca0bf9d5925417fe5a890 SHA-1: 344138c7967a051e18656162c835ac6be015d0ec SHA-256: 1881509cef7502b10ee55a899f183ec9825895b1753714d00e9e74243774ce83
116 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics confirms the malicious intent of directing users to external, potentially harmful, resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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://smidgel.ru/uplcv?utm_term=meilleur+appareil+photo+pour+android PDF link annotation
    • https://nakipoglugroup.com/upload/ckfinder/files/72550935731.pdfIn PDF document text
    • http://rnralpha.cz/res/file/sanixo.pdfIn PDF document text
    • https://hetodon.com/fckeditorfiles/file/korazudazumib.pdfIn PDF document text
    • http://hoshitorionline.com/uploads/files/59275723651.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/vk0rmjpmh1lmppuudsjgvmp6ff/39521021195.pdfIn PDF document text
    • https://aihr-iadh.org/uploads/FCK_files/file/4602086414.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138d45314db0---pukatukudewuvetopedusilon.pdfIn PDF document text
    • http://adriennemason.com/assets/files/92832367364.pdfIn PDF document text
    • https://listocrm.com/userfiles/files/lavipofirojufadiregazep.pdfIn PDF document text
    • https://ijaetis.org/ckfinder/userfiles/files/49192534327.pdfIn PDF document text
    • https://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613967d450c17---33702808505.pdfIn PDF document text
    • http://fpempresa.cen.es/userfiles/files/gimeser.pdfIn PDF document text
    • http://zbigniewrodak.pl/galeria/file/zevufawebevip.pdfIn PDF document text
    • http://tomasmrazek.cz/userfiles/file/jolazesoz.pdfIn PDF document text
    • http://z-him.ru/userfiles/file/zugozitolirevuludituve.pdfIn PDF document text
    • https://gberwanda.com/gbe/useruploads/blogs/files/feguwanizalu.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/89683582141.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c9bdcc6fc---kiluwunogagamojufepalefu.pdfIn PDF document text
    • http://www.tecs4.com/intranet/ckfinder/userfiles/files/70101786635.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/rasajupebajizizeliveba.pdfIn PDF document text
    • https://smartcirclegroup.com/userfiles/file/zedorigow.pdfIn PDF document text
    • http://140.121.161.111/ckfinder/userfiles/files/20909606442.pdfPDF link annotation
    • http://newgoodluckcrane.com/admin/uploadfiles/file/zadedu.pdfIn PDF document text
    • http://sdes.in/uploads/waxivudekitodasadafi.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_off0000d959.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD959 17360 bytes
SHA-256: 3dc4244d747e36e80a8947339faaa35497f4efd62cfeb8fef546978858e78991
font_01_sfnt_off0001053a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1053A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D51 10412 bytes
SHA-256: 49d43c872b56ee5801b36036ac9c5ab493b2b3d0454e49e1bd49f7a044c116e3