Malicious PDF — malware analysis report

Static analysis result for SHA-256 a99f37c6450affbf…

MALICIOUS

PDF

82.6 KB Created: 2021-09-12 02:24:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b07546820ea18b8b4b494e1642c2ef9b SHA-1: 32c1d9d409b63f1e69ab2aa06e3484cd893c744d SHA-256: a99f37c6450affbf7626f8262d39ea3ae06e5fb9cc5e4b5b30e4c135462aba5a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, many hosted on disposable or potentially compromised domains, suggesting a link farm designed to redirect users to malicious content. The presence of a 'download button' heuristic further supports a phishing or social engineering attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://krisoc.ru/uplcv?utm_term=grand+prime+custom+rom PDF link annotation
    • http://adamslakeband.org/userfiles/file/62918813963.pdfIn PDF document text
    • http://liily.jp/upload/file/20210902081432.pdfIn PDF document text
    • http://koreadramatour.com/FileData/ckfinder/files/20210907_73866E5C3505F75B.pdfIn PDF document text
    • https://riondene.ch/img/uploads/file/gujigodugugevamabo.pdfIn PDF document text
    • http://dakmoto.cz/obrazky/file/4807470215.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/suladow.pdfIn PDF document text
    • http://tjchenxing.com/filespath/files/20210903035231.pdfIn PDF document text
    • http://mirutte.com/newsfiles/files/vegivale.pdfIn PDF document text
    • http://vet-arrighicolangelicristilli.eu/userfiles/files/66516689014.pdfIn PDF document text
    • http://tamtamphat.com/upload/files/2326200888.pdfIn PDF document text
    • http://gorsilawfirm.com/userfiles/file/67525485470.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/759930fa5d26d746befd44d0ec62fbde/71369159856.pdfIn PDF document text
    • https://tour-paris-guide.com/cite_imgs/file/68280439441.pdfIn PDF document text
    • http://tutek.eu/userfiles/file/47648192261.pdfIn PDF document text
    • http://madmojo.com/fckupload/file/98171996293.pdfIn PDF document text
    • https://ildiko-szepsegszalon.hu/userfiles/file/30902267488.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16132ba40e4c92---kuraku.pdfIn PDF document text
    • http://tw-echen.com/uploads/files/202109090655062931.pdfIn PDF document text
    • https://ms1oke.com/contents/files/48766869192.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613168f7eeb04---91207133589.pdfIn PDF document text
    • http://aeklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/fopevupor.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/48387279582.pdfIn PDF document text
    • http://kisito.com/userfiles/file/lovijabuxamubepobune.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///gibesesubi.pdfIn PDF document text
    • http://theponghop.com/upload/files/27292828230.pdfIn PDF document text
    • http://firmen-bekleidung.at/userfiles/file/68140267657.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_off0000db3b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3B 10768 bytes
SHA-256: fa0f50d81f898e8e8ef940710096fa5c4840dcc8c81bf78bed634e22647c911e
font_01_sfnt_off0000f3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FA 18724 bytes
SHA-256: f234ef7a5a11aecadf68bc4d58ba43887e04d513372ec337360d8f57542db1c5
font_02_sfnt_off0001248d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1248D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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