Malicious PDF — malware analysis report

Static analysis result for SHA-256 977115d616fcd551…

MALICIOUS

PDF

67.5 KB Created: 2021-06-24 06:32:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 7c74da800b0f6dfc6218da0a6837c12b SHA-1: 31a6b2eb4f280c0ec293a91eb1b1c8a2aab53b1b SHA-256: 977115d616fcd551c02c5f9515c2a24222938620b6d1ab42c622a99f2acf6bbc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file contains a link farm pointing to multiple distinct hosts, many of which appear to be compromised WordPress sites. The document body, though heavily obfuscated, suggests a lure related to academic material ('Aqa gcse spanish textbook answers'). The presence of numerous external URIs and the ML classifier's high confidence score indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://sculecuacumulator.ro/app/webroot/files/userfiles/files/mamibow.pdf In PDF document text
    • http://kme-kme.cz/files/file/mimuretoda.pdfIn PDF document text
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160869bbda8914---votumanumugelapukofuxakug.pdfIn PDF document text
    • http://lotusromeo.fr/app/webroot/files/userfiles/files/29664943522.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/1626039775.pdfIn PDF document text
    • http://www.atrium-tuiles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b74267a31f9---2080432484.pdfIn PDF document text
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/04805166bb88a47de8c5fc248c71184c/jonanivabusejo.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/1608e67b3012c5---3672017018.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c86b0ec5f5a---navidejidotareredel.pdfIn PDF document text
    • http://asirius.su/wp-content/plugins/super-forms/uploads/php/files/bc95eec17696038fe1440773ef60484a/71156844410.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/1606cdf04d9b4b---33983021176.pdfIn PDF document text
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/160ac910f0a7d1---wefudowiwukopovukepibig.pdfIn PDF document text
    • https://www.dazzlingdecor.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1608aca4383efb---93872837516.pdfIn PDF document text
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16079144956770---nobepobanodazotiwapu.pdfIn PDF document text
    • http://itineraire-consulting.com/ckfinder/userfiles/files/wimifikifitogut.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/b697babef26a2f98e166bad610f6a5ce/68992511734.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=aqa+gcse+spanish+textbook+answersPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b305.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB305 5644 bytes
SHA-256: d817f020ff4dba2ae83f0f1b1e4c5fb0577bf86fa8504c3e2fc39d22ceafbcd1
font_01_sfnt_off0000c653.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC653 10664 bytes
SHA-256: 6a3ca6ddb5a0c91852c824dbf1f70aab2b5ed3ac0429b25bf77389e0f4f1aa6c
font_02_sfnt_off0000ead2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD2 16296 bytes
SHA-256: 5561c4d82fbfca81a66c04c36e059cfbf7b6188384656767d3368d526b1af784