Malicious PDF — malware analysis report

Static analysis result for SHA-256 fddf32a41ab7db48…

MALICIOUS

PDF

68.9 KB Created: 2021-09-11 16:19:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d850b2f29a0f00d0033a28efc992190f SHA-1: 778f1c12e008c78ec2fed7c1aacd882459da3b63 SHA-256: fddf32a41ab7db480d37d9f29c29ef83d7e03915e79dc8a1d7c3aed978b6ee85
176 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous links to external websites, many of which are hosted on compromised CMS uploads or disposable domains, suggesting a link farm used for phishing or malware distribution. The malformed stream length heuristic indicates potential exploit activity within the PDF structure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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://www.burnat-provins.ch/ck/ckfinder/userfiles/files/fifajomifezoz.pdf In PDF document text
    • https://portugaliaimagyarok.com/ckfinder/userfiles/files/23403038371.pdfIn PDF document text
    • https://hosrem.org.vn/ckfinder/userfiles/files/15480166317.pdfIn PDF document text
    • https://santehsevast.ru/userfiles/files/2727929777.pdfIn PDF document text
    • https://lightupalife.org.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16138a1f6c1b9b---gifamijiwuturefi.pdfIn PDF document text
    • https://fotobolfestmeny.hu/mvc/userfiles/file/nojaluwuxifujozedojok.pdfIn PDF document text
    • http://akbmodel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f2a23b443---pakumijavojusopek.pdfIn PDF document text
    • http://hidropro.hu/upload/ruwefixem.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/fapewulub.pdfIn PDF document text
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/14406657458.pdfIn PDF document text
    • http://inica.org/files/file///bivoterufulezi.pdfIn PDF document text
    • http://xn--zb0bw3kv4s8mn.com/upload/fckeditor/file/68850934454.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/ir8occjj60prrq8hlvvgt5co21/sedutubawobibas.pdfIn PDF document text
    • https://cardolf.ro/files/25879597800.pdfIn PDF document text
    • https://vashadvokat82.ru/wp-content/plugins/super-forms/uploads/php/files/de698a44915cb8a483ee189b76e4ab10/datexep.pdfIn PDF document text
    • http://skisun.it/userfiles/files/betamefatonev.pdfIn PDF document text
    • http://lexprikson.com/admin/style/images/userfiles/file/75297410964.pdfIn PDF document text
    • http://boissee.fr/userfiles/file/jizazawobekaniguv.pdfIn PDF document text
    • http://techscreening.com/userfiles/files/16555225572.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136ac483092a---vobogunovogabujisapu.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/52443288390.pdfIn PDF document text
    • http://air-ned.com/uploads/files/64969137557.pdfIn PDF document text
    • https://jin-ji.com/upload/files/fixududaditufijaki.pdfIn PDF document text
    • https://anpheatingandac.com/nbloom/fckuploads/file/furason.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+download+pictures+from+android+to+laptopPDF 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_off0000b0cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0CD 14276 bytes
SHA-256: fc1f1c1344309be7727f6db0a9c6d012bf7cfac0baec9b0a36557364a919e81f
font_01_sfnt_off0000d47e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD47E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC95 10956 bytes
SHA-256: 1c061ff8cfff7eb553439bcf821d8f18331ba79c44bda371c3096e863763fee7