Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cab8152e7a73f73…

MALICIOUS

PDF

87.8 KB Created: 2021-09-11 23:10:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 268293d421befe69274fd7e17fbbb2c4 SHA-1: 83a508100023ed52e6407fe8e4639b887b769745 SHA-256: 8cab8152e7a73f73adf0b04a14590bc16e173a7f884535b34758740e5c2bf0fc
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised or disposable hosting. The document body is unreadable, but the presence of numerous external links suggests an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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 http://ikhmongol.mn/ckfinder/userfiles/files/lufis.pdf
    • http://impex-italia.it/userfiles/files/kigijos.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/161399139913d3---39202465323.pdf
    • https://qwert5.com/psum/admin/userfiles/file/zaberisosugedaferuxefig.pdf
    • https://bnovum.hu/downloads/nuvufigatokunerabixef.pdf
    • https://brazilairporttransfers.com/ckfinder/userfiles/files/lokinoti.pdf
    • http://studiomarazzi.eu/userfiles/files/97903485989.pdf
    • http://yeditepegumruk.com/userfiles/7281286396.pdf
    • http://thailaundry.com/imgUpload/files/21268768773.pdf
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/58f240138cc194a659b8714e326e4953/xilubizomorod.pdf
    • https://falconshipping-uae.com/userfiles/files/robasakosarunofomexu.pdf
    • http://bige.vn/uploads/userfiles/file/5248500777.pdf
    • http://jjc-dev.com/userfiles/file/6269257146.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/jg4emp5iht5k6q7oa40r2om1fq/fulobiludukikuzi.pdf
    • https://home-consult.lu/userfiles/files/60601368917.pdf
    • http://www.tamtrebinhminh.com/public/files/38612253971.pdf
    • http://firewaterdamagedfw.com/test/fckeditor/uploadfiles/file/61716937238.pdf
    • http://tarnava.eu/user_images/file/51065841311.pdf
    • http://papienbanana.com/user_file/file/10058735787.pdf
    • http://trieuduong.com/images/Download/38775363644.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b804210c0a---mawoxixedenizowewiniwiku.pdf
    • http://print-printonline.com/ckfinder/userfiles/files/zirutomamilurajotadene.pdf
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613527c0704af---tuzijiwot.pdf
    • https://kuzeyilac.com/resimler/files/vazejidog.pdf
    • http://codienlanhminhquang.com/upload/files/88896808232.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=lightroom+mod+apk+latest+version+2020
    • 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_off0000ed40.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED40 16792 bytes
font_01_sfnt_off00010552.bin
2b61a5ec5c13852175814f7d7a1806b75325fc988eac4492f37105feb520154a
pdf-font-stream PDF embedded font (sfnt) at offset 0x10552 19016 bytes
font_02_sfnt_off00013750.bin
c6b9afd7f1349ca9e43f08563012c836dbf0f6904cab56c800988c5f8bb16afd
pdf-font-stream PDF embedded font (sfnt) at offset 0x13750 11196 bytes