Malicious PDF — malware analysis report

Static analysis result for SHA-256 105c61dea71d27ef…

MALICIOUS

PDF

75.2 KB Created: 2021-09-03 11:01:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a1fa40a45e9869c473d56b1af3e2bb7d SHA-1: beefee3e5e8c09c89fa0e66970cd2c7a7c6c292e SHA-256: 105c61dea71d27efe3e7ed168468c3d267f7259283b1e26af9bf6c4008b4ddcc
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload directories and disposable hosting, indicating a link farm for redirection. The ML classifier and ClamAV detection strongly suggest malicious intent, specifically identified as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites, likely for further exploitation or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 7

  • 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.
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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=history+of+mushroom+cultivation+pdf
    • http://bftt.marketsearching.com/upload/files/18027636974.pdf
    • https://paidionresearch.com/userfiles/files/18636269929.pdf
    • http://allier-genealogie.org/File:/83859254120.pdf
    • http://studioego.cz/userfiles/file/dobinojixiro.pdf
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16120cbd2bc2a9---juvudiwujaliritajabu.pdf
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5d0d726a1---68283586650.pdf
    • http://doo-san.com/userfiles/file/20210630091659.pdf
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/631c418f8871da63cbe3a7796d2e98a5/xopazor.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/60vhomsk8t1chk9qgc5m9qrq11/68390279580.pdf
    • http://k2plusinterior.com/userfiles/4186686436.pdf
    • https://3drm.bg/uploads/pictures/files/55967066509.pdf
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/298et7it8suc5gcgj6eo1rvnfh/29496567390.pdf
    • http://oodow.cn/upload/file/210615035227179250r1722m4bomct.pdf
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/7fskkkq456drkkgflk4q0trl4j/9768652543.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/2d85c846a9b280cfc174a6eb7434cafc/fufemix.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16079a89fb4dab---29754680427.pdf
    • http://sistersaviopublicschool.com/userfiles/file/wowokizazez.pdf
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088564842cde---43562272612.pdf
    • http://maidnheaven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dfa67e0144---29957561943.pdf
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/7e6462842d3f032c92de58b842c41ee2/refajujonip.pdf
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/regalu.pdf
    • http://miamiokclassof65.com/clients/d/db/dbefc63a503cf3d3a4f9fb61678ecc08/File/83614601198.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c076.bin
f70586b0a612338072e3641ab5805ed4bd16a71ba82690a5b3c90a2c53421449
pdf-font-stream PDF embedded font (sfnt) at offset 0xC076 11024 bytes
font_01_sfnt_off0000d9f3.bin
4acdd1d7299f360b318ef1f4b338b7066edfd7b984129b620d635f2d5be1def3
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F3 17636 bytes
font_02_sfnt_off0001078f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1078F 16792 bytes