Malicious PDF — malware analysis report

Static analysis result for SHA-256 f91ec056f1377e70…

MALICIOUS

PDF

84.9 KB Created: 2021-07-17 19:48:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 37fe7ae32dabd8f01bb56f440c656b42 SHA-1: b334436bcfcabde097958cf2fbc69c9620a83748 SHA-256: f91ec056f1377e708d181f5956791401b183e8d92da35e575ae0c48323b0626a
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised websites and disposable hosting, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and unreadable, providing no direct user-facing content but the structure and heuristics point to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://biblioteka-koneck.pl/ckfinder/userfiles/files/vofuvokamibuzumu.pdf In PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160b9c59e551e6---23185142962.pdfIn PDF document text
    • https://europartner2.pl/uploads/52528524150.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2eccb4ca79---72226037185.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c11ef4ae20b---43962750143.pdfIn PDF document text
    • http://industrialsupplies.pk/userfiles/files/47633693870.pdfIn PDF document text
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/23c609c9ac5405dcb00d109e353c40a3/juwonamenip.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/35418879999.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/e1564edee5060bb7a5f19c358c99433f/fekebegijawebup.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/9274499b3f13b4d7439e92188a9f2b24/gesuxonuxugo.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1608fcb05bb0f1---pulamafoto.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/rukjgqm48gqjq7fo8i45vvq843/dixawapo.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/rtjnqci8froe7c6a5vgumt1480/7255738557.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/c00fed2fb164021f92486bf249eedc8e/verarokavomim.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160993f16ef40b---doresidajisurap.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/97189900651.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdcfd877a6c---27329806993.pdfIn PDF document text
    • http://mitcostruttori.it/userfiles/files/tibufoletegopopiwopekowoz.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b5ace927253---1963308687.pdfIn PDF document text
    • http://maility.pl/_ADRESuserfiles/file/7858775753.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/a77be5b0c9a7670662412a2d48035479/sefeziza.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d0067e01692---96795173499.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/91006524013.pdfIn PDF document text
    • https://essaidafm.com/uploads/FCK_files/file/57206101240.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=join+pdfs+windowsPDF 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_off0000ebf7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010409.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10409 16800 bytes
SHA-256: f78beee3f58f30950d7a6e973f9715e0b006519a5d09bb9b06fd2ca17821ff22
font_02_sfnt_off00012fed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FED 10028 bytes
SHA-256: 63bcb8dfc4c347d33bd7d5c6af44360a3c20199fd16cd17ae2eb0ad45faa5f81