Malicious PDF — malware analysis report

Static analysis result for SHA-256 23927f81c4d6c35b…

MALICIOUS

PDF

70.0 KB Created: 2021-09-18 03:11:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 981727911c47c0875748c12f465efaaa SHA-1: b8d4241fd6bddf76bd3e938a8db8e3d14b98536d SHA-256: 23927f81c4d6c35b48963ca5c9bf6f39610b4d84b273f04a88b95629e77d7e70
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including ML classification and ClamAV, indicating malicious intent. The presence of numerous external URLs, many pointing to disposable domains and configured as a link farm, suggests a phishing or malware distribution scheme. The 'SE_CALLBACK_LURE' heuristic further supports a phishing pretext, likely aiming to trick users into clicking malicious links or engaging with fraudulent services.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://ketchas.ru/uplcv?utm_term=peach+emoji+android PDF link annotation
    • http://vevo.keresztessyoptika.hu/elemek/file/88617870051.pdfIn PDF document text
    • https://bustotoronto.com/userfiles/file/72482540762.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/wakavijudizeka.pdfIn PDF document text
    • https://habibitours.org/ckfinder/userfiles/files/takoke.pdfIn PDF document text
    • http://gruppocreta.com/userfiles/files/polavogusozuxetububi.pdfIn PDF document text
    • http://skia22.ru/pic/file/lilixo.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/11493692516.pdfIn PDF document text
    • https://homestayhoian.vn/uploads/image/files/tomepaxusaruxinug.pdfIn PDF document text
    • https://salondumariagededijon.com/userfiles/file/xelabekatowuvapatife.pdfIn PDF document text
    • http://www.giuseppe.ru/ckfinder/userfiles/files/96062200697.pdfIn PDF document text
    • https://atlaskvartir.ua/data/uploads/files/lofutitijedenaluzadewosa.pdfIn PDF document text
    • https://kanat.com/upload/ckfinder/files/76488353781.pdfIn PDF document text
    • http://sahrugs.com/userfiles/file/25153313475.pdfIn PDF document text
    • http://elcwma.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/80827113386.pdfIn PDF document text
    • http://mydreamtuscanwedding.com/editor_up/lovutaliwibepemutujuzef.pdfIn PDF document text
    • https://sharkovinkom.com/sharkovinkom.com/ckfinder/userfiles/files/tuvakelupisemebaw.pdfIn PDF document text
    • https://agri-mal.pl/userfiles/file/nupalizenuto.pdfIn PDF document text
    • http://lorichphoto.com/pictures/file/giwevobowinekofeb.pdfIn PDF document text
    • http://xn--80aamwn.xn--p1ai/userfiles/file/juxobetumelunis.pdfIn PDF document text
    • http://enjoybowlramenandpoke.com/uploads/files/bosijixarowusefaluku.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/39510793502.pdfIn PDF document text
    • http://southportrubbish.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614002880be99---35657716283.pdfIn PDF document text
    • http://mgbig.com/upload_fck/file/2021-9-9/20210909235022540741.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/ckfinder/userfiles/files/8500303048.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_off0000b65a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB65A 14892 bytes
SHA-256: 256091b91d283f26591c9a60e4bd9b3839c969aceb41845dc2f03de6caab9c9b
font_01_sfnt_off0000dac3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f2da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2DA 10456 bytes
SHA-256: 5b26c8ecf4893bfd44b0ae17aadd97e5edafb32c154c6acc19c87aca10d65903