Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc1c528cacca8641…

MALICIOUS

PDF

77.5 KB Created: 2021-07-04 02:33:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f54417c3c7cf8d6f876f51e8b6661add SHA-1: 1baa3e8853b775dda6ca8f6ead1eeb2ee86a5226 SHA-256: dc1c528cacca86416f2d970174c12bd179106beb0532ffbfb84ed11d6dfb429f
156 Risk Score

Malware Insights

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

The file 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 compromised WordPress sites, with numerous URLs pointing to PDF files within plugin upload directories. The presence of many distinct hosts and UTM parameters suggests an attempt to distribute malicious links widely.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://grupogmec.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081b11c9c561---53131373844.pdf
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba1b43f055---rikugepogapo.pdf
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/587jl4sbdrk8lom83c2qp44t41/43242436173.pdf
    • http://bonfiremadigan.com/uploads/fckeditor/file/12006532117.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609bb49f61ff3---13070488584.pdf
    • https://www.nobleorthodontic.com/wp-content/plugins/super-forms/uploads/php/files/a2ed9b18f4ccf55b81901f3b2a3053a8/90538926210.pdf
    • http://yasaitogo.com/uploads/files/34940789767.pdf
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609adb9ea7427---47625755088.pdf
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16083e225c7efd---62499145138.pdf
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/qg73oj6v7gnijcj7mp1labr103/44871341619.pdf
    • https://atlastoursntravels.com/userfiles/file/16494520997.pdf
    • http://ebslang.net/_UploadFile/Images/file/37630357874.pdf
    • https://honghow.com/ckfinder/userfiles/files/76485795524.pdf
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/28469a33e0895796c8669af228e188d5/97871891824.pdf
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607387a16c242---22639296649.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089dac81d66c---8421351798.pdf
    • http://kaztelcom.kz/ckfinder/userfiles/files/61686702911.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9e1baaff7---25335119276.pdf
    • http://www.radio-kum.si/data/files/petamol.pdf
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/d5d678e9de73fb265db30f9dda59815a/vazuxi.pdf
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/1c84b2f334fef0fae975988410dfa4f1/bames.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607bb531061b5---70039867765.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=concrete+truck+weight+full
    • 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_off0000ccb3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCB3 16792 bytes
font_01_sfnt_off0000e4c5.bin
455e85c018df5c8cf441a315924a4f7f83b503782eaaceec5845e09cb85d1026
pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C5 16912 bytes
font_02_sfnt_off000110f6.bin
8f6eb4229fbe7c2070c0c4eeafbe0542833b66c106ace43002de1d6004bf0798
pdf-font-stream PDF embedded font (sfnt) at offset 0x110F6 10592 bytes