Malicious PDF — malware analysis report

Static analysis result for SHA-256 99caa536541bbf06…

MALICIOUS

PDF

76.8 KB Created: 2021-09-12 04:49:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: b32b1ea5bc72358f10828ba623e7a293 SHA-1: 1f2c54d6fbb4c897e7e9673f62961fa196eed413 SHA-256: 99caa536541bbf067d76d4cac4e6185f2e68b1c2792bffe5d7f1b8988c1d874f
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 and appear to be part of a link farm designed to distribute malware. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading a secondary payload. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://alarrabnews.com/images/content/content/file/koxenuzuju.pdf In PDF document text
    • http://yulintimber.cn/d/files/38512187343.pdfIn PDF document text
    • http://liyangah.com/Upload/file/zasejogagulikob.pdfIn PDF document text
    • http://huyndaicaudien.com/upload/files/22030653609.pdfIn PDF document text
    • http://morpheus-architects.com/file_media/file_image/file/maxagopaxanuzilotokipu.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109021319434380.pdfIn PDF document text
    • http://flapboxes.com/userfiles/files/dasawamibowozefireje.pdfIn PDF document text
    • http://ideal-site.ru/userfiles/file/mulekiwaba.pdfIn PDF document text
    • http://gardenofsound.com/userfiles/files/75767705284.pdfIn PDF document text
    • http://sevenseahotel.com/uploads/images/files/gibibajexuwugatoganikefin.pdfIn PDF document text
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/kagupanexuwugofumononop.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/vunujixu.pdfIn PDF document text
    • http://kiddeefire.com/media/userfiles/files/rorilefukubuxojavu.pdfIn PDF document text
    • https://ventadeterrenosurbanos.com/userfiles/file/gamezakoder.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed3313c256---lovojoxeg.pdfIn PDF document text
    • https://robert-zauer.cz/userfiles/file/jilaguseloni.pdfIn PDF document text
    • http://daoltrading.com/userData/board/file/binopemaximexakogagifidag.pdfIn PDF document text
    • http://viettelhaiphong.me/data/dulieu/files/soramerizeru.pdfIn PDF document text
    • http://srtprogetti.eu/userfiles/files/54529040206.pdfIn PDF document text
    • https://geneticapanama.com/userfiles/file/58939140919.pdfIn PDF document text
    • http://domgr11.ru/uploads/files/32297362237.pdfIn PDF document text
    • https://bhsbeacon.com/FCKeditor/file/zemerigelejagigenajuvol.pdfIn PDF document text
    • http://bsp-plovdiv.org/ckfinder/userfiles/files/2028166327.pdfIn PDF document text
    • http://gearcon-eng.com/file_media/file_image/file/77077548794.pdfIn PDF document text
    • http://peter-scherer.de/userfiles/file/114356634.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=let%27s+go+to+prison+full+movie+onlinePDF 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_off0000c856.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC856 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e068.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE068 17136 bytes
SHA-256: 0325c32263bddc78033e1eea1581370d54d0a194dd290a7571afd98f97409d49
font_02_sfnt_off00010ceb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CEB 10696 bytes
SHA-256: 764f20eb6ab9821c9df270b9f7cc439029318fa6d8de26356e21ae9cbad87cee