Malicious PDF — malware analysis report

Static analysis result for SHA-256 81733dc3eb2507c4…

MALICIOUS

PDF

86.8 KB Created: 2021-09-20 09:58:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 5c697f26b20ea8e79ebe7ac730b1ef9d SHA-1: c9ef8bf16c14511840d847429b2049c2af010aea SHA-256: 81733dc3eb2507c43eb9a264f3511f76d91ae0c8d98b48fd5fb9a0412ef8c7ff
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of external links, many of which point to compromised websites or disposable hosting, indicating a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and link farm nature are indicative of an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://cissi.it/userfiles/files/91736208494.pdf In PDF document text
    • http://ahzycw.com/upload_fck/file/2021-9-7/20210907054936873075.pdfIn PDF document text
    • http://xn--rssx31a7tec6p.com/upload/userfiles/files/20210917042551.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/be6hgo41pv8u39adrlofvga0q6/puxufipewo.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/74228578285.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/16147edc6585a5---bukizalozedeses.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/44166159262.pdfIn PDF document text
    • http://resetimpianti.it/reset/public/file/pugugidozarat.pdfIn PDF document text
    • https://at1apigroup3.com/contents/files/90839348725.pdfIn PDF document text
    • http://compagniaviaggi.gattinonimondodivacanze.it/themes/userfiles/files/76551012827.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/161408dcf9a45d---79384825194.pdfIn PDF document text
    • http://obraz-tlt.ru/userfiles/file/39744265293.pdfIn PDF document text
    • https://98ing.com/upload/ck/files/20210911_220315.pdfIn PDF document text
    • http://slmj8.com/data/userfiles/files/gedujar.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/98133872322.pdfIn PDF document text
    • https://paloaltospeakerseries.com/wp-content/plugins/super-forms/uploads/php/files/f91e0371a20b9e2ade7509035ed81f3a/72726721259.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132d1b496773---retale.pdfIn PDF document text
    • https://pasationtravellers.com/root/FCKeditor/file/45362799529.pdfIn PDF document text
    • http://toyotaquangninh.org/data/dulieu/files/59548354226.pdfIn PDF document text
    • http://www.deco-interieure.com/userfiles/file/42682208565.pdfIn PDF document text
    • http://inbeeldt.nl/userfiles/file/95732272169.pdfIn PDF document text
    • http://halanmilk.com/upload/files/88392930592.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16147edd92c389---gerasisolodezuj.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/9b0c4ae82c4a1d69da883d18099766a3/29648143785.pdfIn PDF document text
    • http://abwessex.com/uploads/files/wovenanasuzegujutidawol.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=babumoshai+bandookbaaz+nawazuddin+siddiqui+full+movie+onlinePDF 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_off0000ea96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA96 11164 bytes
SHA-256: cdc83a19699527ec5ea4a12e75e2503cce43e2c3808bf462c5ea23a2e87ad239
font_01_sfnt_off00010465.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10465 18448 bytes
SHA-256: 56bc96a8f96205e340b77bff2b0a504d09d74b6bc12a8254cfe00b1065f97ef1
font_02_sfnt_off0001349f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1349F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1