Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b84cd5660ae30f2…

MALICIOUS

PDF

80.2 KB Created: 2021-09-20 05:32:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 2774b4087f0d5cddeb013dec30e310aa SHA-1: 4d12cfdc9031b941263924c18b09922ae917377e SHA-256: 1b84cd5660ae30f2fa5c474e9f9b1dd72601cd8896d2cccdcaba9f475551e8cd
96 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to what appears to be compromised CMS upload storage, indicating a link farm designed to redirect users to malicious sites. The ML classifier strongly supports the malicious nature of this PDF. The document body is heavily obfuscated and does not provide clear textual lures, but the presence of multiple suspicious URLs and the heuristic firings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://ketchas.ru/uplcv?utm_term=android+app+doppelt+installieren PDF link annotation
    • https://villatoscana-pi.it/userfiles/file/69696792670.pdfIn PDF document text
    • http://szjwwj.com/userfiles/file///72058301258.pdfIn PDF document text
    • https://robustbrakes.com/administrator/imagetemp/file/97871810592.pdfIn PDF document text
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/14214146749.pdfIn PDF document text
    • https://tigapilar.com/upload/files/lemokodoxitizalajugatesew.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/96578463001.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/vukupasawovofakiziw.pdfIn PDF document text
    • https://tourgardan.com/basefile/tourgardancom/files/nekuziluki.pdfIn PDF document text
    • http://scandinavia-ex.com/images/blog/file/tazeb.pdfIn PDF document text
    • http://standdominica.org/files/files/xuzurixifukomafijaz.pdfIn PDF document text
    • http://avanti.pl/userfiles/file/4348504845.pdfIn PDF document text
    • http://longvu.vn/Images_upload/files/xofisozomosijug.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/dd627d5ea19b8177526e47e93016fd95/diwojutewe.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/16141175a29d57---nujiw.pdfIn PDF document text
    • http://artospace.com/pics/file/dowalik.pdfIn PDF document text
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/34915899577.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/9373801c5ef233a5891774e41f3844bb/didoje.pdfIn PDF document text
    • http://architettogherardi.eu/userfiles/files/33969879187.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/bejigozug.pdfIn PDF document text
    • http://showpalmedical.com/userfiles/tisedutegifekevawexuvufom.pdfIn PDF document text
    • https://alebusph.centralcms.cloud/galeria/files/98538013486.pdfIn PDF document text
    • http://prepearl.com/uploadsfile/fasitulukagurebeluno.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/16900971867.pdfIn PDF document text
    • http://liderzy.natura2000.pl/imgturysta/files/93906213831.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161474eb17efa8---xutamumebetifibali.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_off0000d39e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD39E 10368 bytes
SHA-256: f2471c2f62c4a45d194439aa901beffe7ec142feaf0fd9e8906a0db89acff7c2
font_01_sfnt_off0000eb21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB21 18604 bytes
SHA-256: cfa1e1a3e9f1af00c447235b9b76e8309c6a8a3d7152555918db1ddf5f31cb4c
font_02_sfnt_off00011b23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B23 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1