Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a03042f43c1fcb7…

MALICIOUS

PDF

88.6 KB Created: 2021-09-16 21:09:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: e1edc3f21788784bcccf4c685a2684f1 SHA-1: e793dd41b09e388a98f8859b6f5f297d31387fbc SHA-256: 4a03042f43c1fcb7e058823786bf586f4b14ea619ee51c39d6802c915641df40
246 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF document contains numerous links to other PDF files, many of which are hosted on disposable domains, indicating a link farm. The document body explicitly mentions 'Zip file password cracker android', suggesting a lure to download a password-protected archive. This tactic is often used to bypass security scanners, with the actual malicious payload hidden within the archive and its password provided separately. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Recovery secret / private key request critical SE_SECRET_RECOVERY_LURE
    Document requests recovery phrases, private keys, backup codes, or saved passwords. Requests for these secrets in a document are high-risk.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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) or Microsoft license-boilerplate 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 http://dolekkoyum.com/admin/UserFiles/file/36111493439.pdf In PDF document text
    • http://luligang.com/ckfinder/userfiles/files/nagitetufizuwudu.pdfIn PDF document text
    • https://autosaloncenter.com/uploads/files/82835930920.pdfIn PDF document text
    • http://boki.hu/editor_up/56349026343.pdfIn PDF document text
    • http://gongin.humenia.com/upload/userfiles/2021/09/files/210904225133.pdfIn PDF document text
    • https://aiwatopup.com/ckfinder/userfiles/files/feforopavamebolulo.pdfIn PDF document text
    • http://marinaxaraes.com.br/ckfinder/userfiles/files/4171154985.pdfIn PDF document text
    • http://embeddedhr.com/ckfinder/userfiles/files/vuzokemuve.pdfIn PDF document text
    • http://all-vehicle.net/js/upload/files/47664702254.pdfIn PDF document text
    • https://pecintajp.com/contents/files/notasijizilonoporizabufiv.pdfIn PDF document text
    • http://aibasylhet.edu.bd/app/webroot/ckfinder/userfiles/files/saredotam.pdfIn PDF document text
    • http://www.nagsa.es/ckfinder/userfiles/files/donojebozokivogekipodis.pdfIn PDF document text
    • https://breedlife.com/upload/files/mubuwubowelejiwixilero.pdfIn PDF document text
    • http://debseven.net/UserFiles/File/tunara.pdfIn PDF document text
    • https://rowanmkt.com/Uploads/ckfinder/userfiles/files/50912918739.pdfIn PDF document text
    • http://kooijobs.in/ckfinder/userfiles/files/fozononowosi.pdfIn PDF document text
    • http://auto-rad.pl/userfiles/file/godekiminetilonaxixanox.pdfIn PDF document text
    • http://hotelgiottotorino.com/userfiles/files/gapot.pdfIn PDF document text
    • http://oppedisanorobertosrl.com/userfiles/files/luliwevuvufawidubejuwetiw.pdfIn PDF document text
    • https://bluetact.com/locktactyuma/userfiles/file/50317384250.pdfIn PDF document text
    • http://a1-automotivegroup.com/upload/files/baremosanuxowikogu.pdfIn PDF document text
    • https://niboparis.com/upload/fckeditor/file/1630594252_1.pdfIn PDF document text
    • http://nanoservice.cz/upload/file/25538618200.pdfIn PDF document text
    • https://austdoorcaocap.com/upload/files/48222976846.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/71ev7e6n3pnodh3of6kql8jjtv/binowowup.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=zip+file+password+cracker+androidPDF 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 extracted file (font_00_sfnt_off0000ef88.bin)
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn extracted file (font_00_sfnt_off0000ef88.bin)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ef88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF88 19872 bytes
SHA-256: 144274f65245e11593763a1ca407823b01ad5323644577fc599a74971780dc3b
font_01_sfnt_off000123df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123DF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013bf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BF6 10656 bytes
SHA-256: e84c18b6f37ac540f9a02f71a45398f77984a84e0a681bc5db15e7f19c435bac