Malicious PDF — malware analysis report

Static analysis result for SHA-256 613da6db1c55b1cc…

MALICIOUS

PDF

86.8 KB Created: 2021-07-24 09:05:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 79570ad76dae6c29267a43f08c325e4e SHA-1: 78e6a9504753735310f48886d686c4eeb23a9fca SHA-256: 613da6db1c55b1cc01f1eb5d3824f2824a0015ed912cd78324dfc6a352206636
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external websites hosted on various domains, some of which appear to be compromised CMS instances. The presence of numerous URLs, many pointing to PDF files on potentially compromised sites, suggests an attempt to distribute malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://atek-ent.com/upload/file/71017341133.pdf
    • https://www.hsbofmn.com/ckfinder/userfiles/files/womekuxexiratebifoniguj.pdf
    • https://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/b76486345592ae885a9cc38f7b1a9e38/20813488448.pdf
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc072b22a7---deputetatatomag.pdf
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160712e672e252---80914562101.pdf
    • https://giga-tronics.com/userfiles/files/koguzajelevajapugo.pdf
    • http://lovemyskindayspa.com/clients/d/d9/d99ed7cf7cbac978b7326c22a81d1608/File/94367615108.pdf
    • https://marljivo.hr/userfiles/file/2473867938.pdf
    • https://www.analfissur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606efb443f802---puloxuzaxivejo.pdf
    • https://sancarspune.com/wp-content/plugins/super-forms/uploads/php/files/abac2e9df14fae1a27464a0d649047c1/ziwebepud.pdf
    • https://alnahamgroup.com/userfiles/file/66408849421.pdf
    • http://derkwoo.com/upload/editor/files/nawuwodulozigefivig.pdf
    • http://osoboebludo.com/ckfinder/userfiles/files/40383063931.pdf
    • http://www.haztartasigepszakuzlet.hu/pics/file/5515978600.pdf
    • http://k-yoga.org/file_upload/spaw_upload/file/20210503053353.pdf
    • https://perfecthospital.org/FCKeditor/file/wazolanilewomatupimofasi.pdf
    • https://dacinsara.ro/fckfiles/file/pidutuminezasaxemolavunib.pdf
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/8a73e532c78735d2c501de065ea5d987/93224206938.pdf
    • http://hocikto.info/userfiles/file/14275176350.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e5b8aaad14b---sewepaperusi.pdf
    • https://www.erenang.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089e1bb82b97---34317605277.pdf
    • http://deborahbrown.us/clients/860103/File/2992513073.pdf
    • http://brezov-gaj.si/uporabnik/file/9351683737.pdf
    • https://cqc-material.com/app/webroot/userfiles/files/73801103623.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=where+is+the+next+barrett+jackson+auction
    • 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_off0000f171.bin
b8e1a3eb6c6f5ff36588bf2bab32048ceb0db52ab6379e01c28825e230a666b3
pdf-font-stream PDF embedded font (sfnt) at offset 0xF171 16252 bytes
font_01_sfnt_off00011b8e.bin
123306004e0a4ee8829cb12d28c61b00d27356c8b2248d52b6c1dd54d947dfd4
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B8E 10840 bytes
font_02_sfnt_off000134a1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x134A1 16792 bytes