Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f5f0cbd8e2b98bf…

MALICIOUS

PDF

81.8 KB Created: 2021-10-06 16:34:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: edfce11062cfcb3680ad4bfb3d845b0f SHA-1: ff69a20f66cc7901ab43d250c22c8ef5ca2f5476 SHA-256: 1f5f0cbd8e2b98bfc8c1d10a74a87f5d3ba0c59e83267d5172c8bcca704c27d6
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with several heuristics indicating it functions as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were directly extracted, the PDF structure and numerous URLs point to an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://gusanhightec.com/userData/board/file/39599121549.pdf In PDF document text
    • https://tierrettung-in-katalonien.org/ckfinder/userfiles/files/57770915486.pdfIn PDF document text
    • https://kingyao.com/uploadfiles/files/20211004_182545_3160.pdfIn PDF document text
    • http://hermanosgolbano.com/admin/fckeditor/editor/filemanager/connectors/phpfile/tonupilifusadisatibirukin.pdfIn PDF document text
    • https://interangkorcondominium.com/userfiles/file/58780173912.pdfIn PDF document text
    • http://honghuibio.com/d/files/riwirotudak.pdfIn PDF document text
    • http://ros-grad.ru/fck_editor_files/files/wonegu.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/pevaliwibudogoludirodani.pdfIn PDF document text
    • http://mcutech.net/upload/2021/09/file/1631235003775976066.pdfIn PDF document text
    • http://vaynhe.com/upload/files/kafesenas.pdfIn PDF document text
    • http://elektromig.pl/userfiles/file/50588824329.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/kapezifasuzelagudezeju.pdfIn PDF document text
    • http://atem.sciara.eu/public/upload/file/bopagudenagutikuwu.pdfIn PDF document text
    • http://ambulatorioveterinariosantanna.eu/userfiles/files/buseses.pdfIn PDF document text
    • http://sevimticaret.net/userfiles/file/kipetuvufu.pdfIn PDF document text
    • http://urbanelect.com/userfiles/file/35542703762.pdfIn PDF document text
    • https://granitabrasive.ro/editor_up/26865775881.pdfIn PDF document text
    • http://bndweb.nl/upload/files/dinum.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/35645758857.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210911094340.pdfIn PDF document text
    • http://sitoad.com/bbqjoekey/files/202109030529185977.pdfIn PDF document text
    • https://riosemarescentrodemergulho.com/ckfinder/files/30358589804.pdfIn PDF document text
    • http://studiotecnicofrisoli.com/userfiles/files/40486650168.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=7th+grade+books+to+read+online+freePDF 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_off0000d884.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD884 10820 bytes
SHA-256: 3b2878faad0e286f2fcc1edf01459b3ec2adde26018966e6d6e9032de935feb7
font_01_sfnt_off0000f12e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF12E 18420 bytes
SHA-256: ea2ff7a06eca4edf4c15cc8d01a66015d61a098c6857083fcb77299c561fab54
font_02_sfnt_off00012106.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12106 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1