Malicious PDF — malware analysis report

Static analysis result for SHA-256 6253aa91d4b2f6ac…

MALICIOUS

PDF

70.1 KB Created: 2021-09-10 02:32:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: d3d3f7332eef877f68bf0c1cce7a5d39 SHA-1: 71a4c5510c5d17b89ae3685b40aa9a98fc8380d8 SHA-256: 6253aa91d4b2f6ac3e3b960fb0ca7d2d8f4b2acf9249f239d80052b3772f5e89
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, with a high-confidence heuristic identifying it as a link farm on disposable hosting. The ClamAV detection and ML classifier further indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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
  • 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 https://infrive.ru/uplcv?utm_term=android+hack+book+pdf PDF link annotation
    • http://muacuoi.vn/Pictures/files/65959059625.pdfIn PDF document text
    • http://fra2ange.it/userfiles/files/62463942207.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/37759647989.pdfIn PDF document text
    • https://carcarnet.com/home/sandbox/domains/hkdance.tritek.hk/public_html/ckfinder/userfiles/files/24957959055.pdfIn PDF document text
    • http://vivatbacchus.hu/files/file/jelumajuwiniwa.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210903115053.pdfIn PDF document text
    • http://rallyteamwalraven.nl/file/dixoki.pdfIn PDF document text
    • http://myphamvickwhitebeck.vn/luutru/files/87098659139.pdfIn PDF document text
    • https://upbilbao.com/ckfinder/userfiles/files/51014966316.pdfIn PDF document text
    • https://gdaniec.com/upload/files/77148357636.pdfIn PDF document text
    • https://serviceelectric.ca/userfiles/file/kikuxavixivivapuvekaresot.pdfIn PDF document text
    • https://learn-atdi.com/uploads/files/zivobudufiparalapiliw.pdfIn PDF document text
    • https://sibconsulting.com/contents/files/51580570354.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/40977693722.pdfIn PDF document text
    • https://attack.lt/images/files/13339475803.pdfIn PDF document text
    • https://network-italia.it/file/53176385193.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/kabege.pdfIn PDF document text
    • https://proxus.nl/file/95037428142.pdfIn PDF document text
    • https://livermore.com/wysiwygfiles/file/pafij.pdfIn PDF document text
    • https://projektovanje.info/userfiles/file/13371207752.pdfIn PDF document text
    • http://thongthien.vn/upload/files/47859582800.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/gajasafapijitateveboku.pdfIn PDF document text
    • https://internationallanguagenavigators.com/media/pabuvon.pdfIn PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/2467186154.pdfIn PDF document text
    • http://diplomat2014.ru/ckfinder/userfiles/files/gevubexaw.pdfIn PDF document text
    • https://thaiwoodengames.com/files/upload/files/kerajaniwogitedaregan.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_off0000b371.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB371 10484 bytes
SHA-256: 4d5723eb02fa6563fa982203f69d33594c6b52d99dbd8b20f80bb250594117d5
font_01_sfnt_off0000caeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAEB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e2fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2FD 15708 bytes
SHA-256: 7383fd5a7bcfdf40abd6e3eb5cd415f3603c3bf0ce427f01fafd5b14b81a4819