Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4b3041dab2775b9…

MALICIOUS

PDF

90.8 KB Created: 2021-09-03 05:54:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b0661f251d1f285d0cddb4355c000f66 SHA-1: d73e5d06c9930144c4822f0101de3be9bd164bd5 SHA-256: a4b3041dab2775b988da081c95ac0156ecce23711b4453166c7dbe83c803fec5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm hosted on disposable domains, suggesting it's designed to redirect users to potentially harmful sites. The presence of numerous unknown URLs further supports this, as they likely serve as the final destinations for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://dailygiasi.com/uploads/userfiles/file/nuruzegepilipaxol.pdf
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a91deca8e5c---95704229261.pdf
    • http://mistral-paints.cz/userfiles/files/tujuragenenela.pdf
    • https://bataretak.com/img/files/file/16293597071.pdf
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/160df6d2a42f27---wuwisipakenazegakajunan.pdf
    • https://livredart.com/ckfinder/userfiles/files/93316478958.pdf
    • https://acryl-bg.com/userfiles/file/bufedoliwazatuxip.pdf
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1607f21783ccbd---lakatimonabaxekin.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d35fae8342---somim.pdf
    • https://copab.tn/216mag.svn/uploads/files/vofuvazesabofiguvegokizu.pdf
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d2ec015a1---jinewokagilezubapidag.pdf
    • http://gyobel.it/public/file/8924398742.pdf
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea9df7a562---jedenonepezinam.pdf
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/k6rp59u5atsh12l14g9oo9qqq2/8330546564.pdf
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/c4gs2hku60rptaj6r08nd9bsg1/vozaxejabanivesa.pdf
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/48605faded8ee1f7d8bc6e1e5b0b4a27/43050455692.pdf
    • http://elturo.ru/img/upload/files/liker.pdf
    • https://legyenegyjonapod.hu/userfiles/files/62230731550.pdf
    • http://malifer.hu/upload/file/10250637826.pdf
    • http://agriturismocorteerbatici.it/userfiles/files/91247667463.pdf
    • https://lightspec.com/wp-content/plugins/super-forms/uploads/php/files/7520daf63c4f125e26089927252cc081/91970951351.pdf
    • http://agapetown.net/ckfinder/userfiles/files/87035479042.pdf
    • http://learningkey.org/userfiles/85535688355.pdf
    • http://packturf.fr/files/pixilenupadubawoxaveseri.pdf
    • https://marljivo.hr/userfiles/file/nuxowalimekuvu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=programme+pmuc+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_off0000fa51.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA51 16792 bytes
font_01_sfnt_off00011268.bin
3aaec437d19d5f5c7a17706d50287ac15147264c71845528b14b987afe8b6ca5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11268 10556 bytes
font_02_sfnt_off00012a4a.bin
b72ce13cbfa62c983345f0b8d9045ed6b90ea365ddfe87da0ab3fe51a4b07f41
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A4A 19856 bytes