Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa43d4976f86e1cd…

MALICIOUS

PDF

72.7 KB Created: 2021-10-03 02:51:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b4e2d2461932cee62917f6df607e77ce SHA-1: fba9bc11f7ad74d8262f2df48d97b6bc001bfa56 SHA-256: aa43d4976f86e1cd89b2ef9804d2df2870bc6ba41d5b0e0bc32e954747e50438
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of embedded URLs, many pointing to disposable domains, suggesting a link farm or phishing lure. The presence of external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly support this attack pattern. No scripts were extracted, but the overall structure and URL distribution are characteristic of phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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://inwebjor.ru/uplcv?utm_term=time+series+forecasting+statistics PDF link annotation
    • https://zapret-rf.org/web/img/podborky/files/28456752456.pdfIn PDF document text
    • https://chulintemple.org/CKEdit/upload/files/3382680844.pdfIn PDF document text
    • http://sakesushilakehavasu.com/uploads/files/wimivafaxavif.pdfIn PDF document text
    • http://kasargod.net/uploads/file/wasakob.pdfIn PDF document text
    • http://3e3i.com/UserFiles/file///35437265104.pdfIn PDF document text
    • http://hotelrefah4ter.ir/basefile/hotelrefah4terir/files/38578013204.pdfIn PDF document text
    • http://ryukatsu.com/userData/board/file/96322856441.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/libapij.pdfIn PDF document text
    • https://forumsevens.com/images/file/suwotokeluz.pdfIn PDF document text
    • http://oiseau-bleu-morzine.com/userfiles/file/mugapis.pdfIn PDF document text
    • http://guss-ex.de/uploads/fck/file/44164033459.pdfIn PDF document text
    • http://specimport.by/files/files/zikovezejuju.pdfIn PDF document text
    • http://mishelik.ru/userfiles/file/97345906747.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613421bf06e17---jotoki.pdfIn PDF document text
    • http://webcertain.asia/contentupload/fckeditorUploads/organization_/file/waxejufanagazutatituniki.pdfIn PDF document text
    • http://phuquytravel.com/nguyenvanlinh/files/xofuwaforenexumogat.pdfIn PDF document text
    • http://hemeringen.de/ckeditor_ablage/userfiles/files/bidifogabogonaru.pdfIn PDF document text
    • https://adamslakeband.org/userfiles/file/gojemima.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/12071520292.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/062e0d92b2dfd48719f91ea92adfd4b1/daludige.pdfIn PDF document text
    • http://wooshin.kr/uploaded/file/1697583113614595d36f262.pdfIn PDF document text
    • https://greenlakepaint.com/ckfinder/userfiles/files/roxobalakajeligusimafezof.pdfIn PDF document text
    • https://kildevangen.dk/files/notabasakiwove.pdfIn PDF document text
    • https://advantagelic.com/singhania/downloads/file/toxozoniserepon.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/51560936157.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/9776968698.pdfIn PDF document text
    • https://casadko.fr/userfiles/file/nodozigomodura.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_off0000b7d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7D3 17240 bytes
SHA-256: 13cc6fcdccbf6ba5d1b699007c188fb710d32a4c39f5b093a4f319e64c54232c
font_01_sfnt_off0000e46b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE46B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC82 10596 bytes
SHA-256: 5c6fbfe2a41419a17de036c8420a3a2dd4fe112c201aad771c2061c67d1a2c68