Malicious PDF — malware analysis report

Static analysis result for SHA-256 f497c191051685e2…

MALICIOUS

PDF

80.3 KB Created: 2021-09-11 12:57:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 1ebdc8c61a539c4b6ead58e01287a7c4 SHA-1: 666bb741ae5df0aa3b6e73c28208523bdc1aaf4b SHA-256: f497c191051685e285eaf54d6cb4f3cce9496d87808d067d01e4d9f01a0606e6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external resources, many of which are hosted on disposable domains, indicating a link farm designed to distribute malware. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of embedded URLs and the PDF_RANDOM_URL_LINK heuristic point towards an attempt to redirect the user to malicious content, likely a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://k3projekt.pl/uploads/userfiles/files/bovozepekunafivikibapi.pdf In PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/1613a06f254d79---45237041703.pdfIn PDF document text
    • https://tigapilar.com/upload/files/9154817184.pdfIn PDF document text
    • http://rrmkaryacollege.org/rrmkarya/userfiles/file/39595347803.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/99330009005.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/sijefivirefopa.pdfIn PDF document text
    • https://sandp-engineering.com/ckfinder/userfiles/files/nadamases.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/4538e840c74175e3d1090ab184faecc7/20763020870.pdfIn PDF document text
    • http://nsk-nalogov.net/upload/files/badizogajafurazu.pdfIn PDF document text
    • http://csc0851.com/userfiles/file/20210906164919_k4tnyr.pdfIn PDF document text
    • http://alanaf.ru/userfiles/files/26625876068.pdfIn PDF document text
    • http://redondoclassicburger.com/uploads/files/71270492019.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/xekararegelepipadisani.pdfIn PDF document text
    • http://vektorma.ru/uploads/assets/file/65936914910.pdfIn PDF document text
    • http://4bzsoftware.com/Images_upload/files/44761886740.pdfIn PDF document text
    • http://e-motyle.natura2000.pl/imgturysta/files/likotiketosexuxebiwo.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/wofekepokeruwoxujizil.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/wufixurawawevat.pdfIn PDF document text
    • http://aktifimmo.lu/userfiles/files/fumobokunex.pdfIn PDF document text
    • http://mensagemcrista.com.br/ckfinder/userfiles/files/86402666331.pdfIn PDF document text
    • http://goldendoodlesofthesierranevadas.com/userfiles/file/fopajavuf.pdfIn PDF document text
    • http://ivelinabozilova.com/userfiles/file/43862067341.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=sample+desktop+applicationPDF 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_off0000d727.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD727 17088 bytes
SHA-256: 47d555df56c463278e2d1447342009da4056ff2778d25c9a4d9a348361f66560
font_01_sfnt_off00010370.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10370 10744 bytes
SHA-256: bf7b99723a90c3d46ecc45ad561328eb1c3c194f4d038bfc1d16308ef381b1b1
font_02_sfnt_off00011c18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1