Malicious PDF — malware analysis report

Static analysis result for SHA-256 3da099ab871aeb2c…

MALICIOUS

PDF

83.0 KB Created: 2021-09-08 13:58:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8cca728760c804aba6dc11db370660c3 SHA-1: 2403e37f5fd75f82f6eb9b831c133c6a1fe1e95d SHA-256: 3da099ab871aeb2c854195c092b2ecc8142f2abcb49b2108b10c56be35b4a7cd
156 Risk Score

Malware Insights

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

The sample was identified as malicious by a machine learning classifier and ClamAV, flagging it as a potential phishing or trojan PDF. Heuristics indicate it functions as a link farm, directing users to multiple disposable or compromised domains, which is a common tactic for phishing or malware distribution. The embedded URLs and the PDF's structure suggest an attempt to redirect users to external, potentially malicious, content.

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 https://doellefjelde-mussemarked.dk/images/newsmail/file/sozifoxadezejumi.pdf In PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136efea7ef4c---towaramuwewo.pdfIn PDF document text
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161335e24c5448---xipegadixaronopajow.pdfIn PDF document text
    • http://metrocars.london/survey/userfiles/files/doxametuvaf.pdfIn PDF document text
    • http://dichvutheapec.com/upload/FCK/file/newutexesimela.pdfIn PDF document text
    • http://talesma.com/E/file/xilik.pdfIn PDF document text
    • http://cleanking.net/userData/board/file/feradiridaninilesawulupum.pdfIn PDF document text
    • http://freewest.at/13793145316.pdfIn PDF document text
    • http://okeefesreef.com/ckfinder/userfiles/files/51049145748.pdfIn PDF document text
    • http://rewitex.pl/userfiles/file/71022837689.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/94739561959.pdfIn PDF document text
    • https://laughteronlineuniversity.com/images/upload/files/81229128036.pdfIn PDF document text
    • http://polimak.pl/userfiles/file/14087629495.pdfIn PDF document text
    • https://baigiangtoanhoc.com/upload/files/36674484252.pdfIn PDF document text
    • https://maintogelonline.info/contents/files/23875813686.pdfIn PDF document text
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161334da63de83---45363294390.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/56befa963c8a2e4da6ed3f8317fb4010/lokabasidexopijalap.pdfIn PDF document text
    • http://www.pilartangguh.com/file/3380062854.pdfIn PDF document text
    • http://hanabi-la.com/uploads/files/toxulezopekafenukokat.pdfIn PDF document text
    • http://xn--o39a91gvwm83kbsn.com/FileData/ckfinder/files/20210907_F4E03D9A0577CDF5.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/91399490537.pdfIn PDF document text
    • http://babyindex.nl/images/uploads/xavawabuvenozexaveme.pdfIn PDF document text
    • http://parentini.it/userfiles/files/46679084430.pdfIn PDF document text
    • http://danchrisjewelry.com/userfiles/file/lidam.pdfIn PDF document text
    • http://poliinc.com/upload/files/turoxafetiserok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=hypothyroidism+diet+plan+pdfPDF 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://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_off0000df17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF17 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f72e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF72E 10868 bytes
SHA-256: 24f604bda0de0aae7c1fddf45bef4773c14b6559ed5260cb1f22b9503e2cf071
font_02_sfnt_off00011012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11012 17724 bytes
SHA-256: 04aca0a154363ce24d6f3bcb12b67ecd480324e0bc93b7b3b834dd36f45d7082