Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3ffebedffd53fc8…

MALICIOUS

PDF

84.4 KB Created: 2021-07-05 06:07:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: bb41f7ea012d2ac9176166c44ce02668 SHA-1: 753e45336123342d8addca0029f1ee4a3842e517 SHA-256: a3ffebedffd53fc8e69229c4fec51a955c008cfbc654a8ab9d715f2cd21af02d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites, likely intended to lure users into downloading further malicious content or submitting sensitive information. No scripts were extracted, and the document body was heavily obfuscated, preventing a deeper analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://coretry.ru/uplcv?utm_term=multi+step+equations+with+variables+on+one+side
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160869149b9e0e---fizizavakumasulabuxopu.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a30674d998c---34499112383.pdf
    • https://arenda1s.ru/wp-content/plugins/super-forms/uploads/php/files/16b1c1d6a0add36c7b952a25d6af69b8/35667238919.pdf
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/66e69e3c7a2c78e4f1c55eb76f421166/28628700140.pdf
    • http://tubietelbar.hu/uploadfile/17806363294.pdf
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607945cd6efe0---84783363769.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3e41ea3307---filobekafo.pdf
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/ge2sjr5qtmdaos3ril7lg75smg/jewuw.pdf
    • http://hkalc.com/userfiles/20763134791.pdf
    • http://doyen.cc/images/upload/File/90208493796.pdf
    • https://pensiuneavlasin.ro/wp-content/plugins/super-forms/uploads/php/files/7cgov12osjoibgsoel02tih9f4/16064508467.pdf
    • https://presstone.hu/userfiles/file/54244648381.pdf
    • https://fotobolfestmeny.hu/mvc/userfiles/file/xixufugobojobal.pdf
    • https://animaliadielisa.com/file/kirebuwefepokopuz.pdf
    • https://k2salight.com/wp-content/plugins/super-forms/uploads/php/files/b8fc6bd69fde18ce9b14d97239e1228a/gonatiwukukatutetiposim.pdf
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/wujikedufagivuwuw.pdf
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/ee738b0a814ca7c1aa5a5a7d49e822ab/74396809019.pdf
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160881ba905315---wupupaxujupuwugoxek.pdf
    • http://akinmedical.com/uploads/file/6621652386.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bef5ddee9bb---32973564673.pdf
    • https://rubyyadav.com/nbloom/fckuploads/file/kutekuga.pdf
    • http://aldara-latinoamerica.com/userfiles/file/12240002901.pdf
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/08dff24b5d6c5709674143daebbfca45/medumekaguwesunutize.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_off0000e76f.bin
ab35597126772f830fbbcd4494d6cfa3f0a6406bf70de3764a5565f0343552ae
pdf-font-stream PDF embedded font (sfnt) at offset 0xE76F 11020 bytes
font_01_sfnt_off0001009a.bin
63e2a62c3518a8a0c4b7f2380cee53252f658c2b18c95592e5c3f5c3d33380a2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1009A 16704 bytes
font_02_sfnt_off00012c37.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12C37 16792 bytes