Malicious PDF — malware analysis report

Static analysis result for SHA-256 99ef31a711de60fc…

MALICIOUS

PDF

83.3 KB Created: 2021-06-25 12:48:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 116157c6f4d11be05f96a2fec5104375 SHA-1: 76b3804c2d16e15e0b98054066aa866afdc2f5b3 SHA-256: 99ef31a711de60fc434725d5003db736d4786370787f9daa74544de341896d5e
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristic firings indicating it is a malicious document, including random and compromised CMS upload links. The ClamAV detection and ML classifier strongly suggest malicious intent. The presence of numerous external URLs, many pointing to compromised WordPress installations or disposable hosting, indicates the file is designed to redirect users to potentially harmful content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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=adding+and+subtracting+rational+expression
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/7v4n3s03bstdacelrbmi8n1q9h/83225925864.pdf
    • https://orldoc.ch/wp-content/plugins/super-forms/uploads/php/files/ttolhv1qjfhg0gfgre01f562c7/79205191273.pdf
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a921aaa2266---garix.pdf
    • http://blesk-stroy.ru/userfiles/files/zodigataraworarategubif.pdf
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f93f8ab4f5---73890977479.pdf
    • http://castudio.eu/userfiles/files/wipikidigilowuv.pdf
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609df0120f8cf---jajitewaxotejexovowug.pdf
    • http://sochisushi.nl/survey/userfiles/files/bexoboxuzepepubogosapori.pdf
    • http://ganan10.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160883fd31010f---nipikufabexiwof.pdf
    • http://aczelzalog.hu/tmp/45933438785.pdf
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c071c4bd842---jirifilatezaxuxi.pdf
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608a336e130d6---wonarokanubeluba.pdf
    • http://vce34.ru/attachments/file/basogejukupupevomilez.pdf
    • https://bda.ch/ckfinder/userfiles/files/netuxuruloxixutevoduwopok.pdf
    • http://jfac.kr/ckfinder/userfiles/files/44142610097.pdf
    • http://artistalexanderkanevskywinnerinternationalaward.com/clientMedia/file/xowif.pdf
    • http://nordicaluminium.ru/userfiles/file/95051633266.pdf
    • http://aite-materials.com/upfiles/file/supudesalelulegeboniniwi.pdf
    • http://dekoblickfang.de/userfiles/file/70513099834.pdf
    • http://goldenbaycruisesagent.com/userfiles/file/jekufuri.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_off0000e15b.bin
909147ff626df0bea75facf7505490393a89d737f68a0760ba8f94d9b6743901
pdf-font-stream PDF embedded font (sfnt) at offset 0xE15B 16944 bytes
font_01_sfnt_off00010ce5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE5 16792 bytes
font_02_sfnt_off000124fc.bin
1e2c43d07f6f76e194153f40cd0fbaf8d55d69ee41bacc3ec3990540d05633e4
pdf-font-stream PDF embedded font (sfnt) at offset 0x124FC 11012 bytes