Malicious PDF — malware analysis report

Static analysis result for SHA-256 10f88dc26c5b6025…

MALICIOUS

PDF

80.7 KB Created: 2021-09-16 15:29:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: dc2c4694cfe825c3e8b6f3026c4a26af SHA-1: 03815426a7b059f0da5ad33426b016056fa872d1 SHA-256: 10f88dc26c5b6025597d4afdb7c64fcef1770b0cd27d96143b745070996ce8a0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to disposable hosting and appear to be part of a link farm, a common tactic for phishing or malware distribution. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a strategy to obscure the true destination. While no scripts were explicitly extracted, the nature of the embedded URLs and the heuristics suggest the PDF is intended to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://abdon.madteam.net/ckfinder/userfiles/files/35106365268.pdf In PDF document text
    • https://clubsecurite.fr/webroot/upload/files/sorunibanovilukegufukufar.pdfIn PDF document text
    • http://badaranquehablar.com/userfiles/files/xudajejamoxifinixijuna.pdfIn PDF document text
    • http://heaig.org/editor/ckfinder/userfiles/files/70973492687.pdfIn PDF document text
    • http://gcoekmr.org/cukashmir/User_Files/imagefile/lubamozotejib.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/varinetizub.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612f01a279e80---vazifefaxutomajut.pdfIn PDF document text
    • https://umutisi.com/umut/upload/files/80832986242.pdfIn PDF document text
    • http://bon-mar.com/fck_user_files/file/66373006369.pdfIn PDF document text
    • https://sikdercollegeofpharmacy.com/scp/ckfinder/uploads/userfiles/files/74787992373.pdfIn PDF document text
    • https://santaclara.com/wysiwygfiles/file/fumivosaluvu.pdfIn PDF document text
    • http://opusbiz.kr/data/editor/file/80490270361391943c77d7.pdfIn PDF document text
    • http://mu-rrrc.com/userfiles/file/satewisujukiveferexizepu.pdfIn PDF document text
    • https://www.lipca.com/ckfinder/userfiles/files/fuseraloluriruzi.pdfIn PDF document text
    • http://capesociety.ca/uploads/files/sidax.pdfIn PDF document text
    • http://xn--80aafbkbafwdti1ahihccrg.xn--p1ai/pict/file/sisovebitizeme.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/43544553640.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/jajidolisevib.pdfIn PDF document text
    • http://julianina.de/upload/file/72632740174.pdfIn PDF document text
    • http://rowadhr.com/app/webroot/upload/files/40853446115.pdfIn PDF document text
    • http://geteffective.biz/uploadfiles/file/pazofaxigunomaruronepiso.pdfIn PDF document text
    • http://obasekiestates.com/UserFiles/file/josidufobizowakoxezepipa.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/47368069183.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614188fdada2e---20368491481.pdfIn PDF document text
    • https://tradingphrases.net/userfiles/files/42207111221.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/megur.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=grand+theft+auto+5+mobile+apkPDF 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_off0000d73e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD73E 17352 bytes
SHA-256: 80ac8b201c574b69c3b165153bb8e5fde8973c26b8dcbc05747977c651e862b9
font_01_sfnt_off000103c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C6 11100 bytes
SHA-256: 497af49ce46a8597da2ec0470cbdb4659a253c165f6731ff62570d1c366f5cd5
font_02_sfnt_off00011d3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D3E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1