Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cc18159f631fcb4…

MALICIOUS

PDF

89.6 KB Created: 2021-08-15 02:46:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 78e755e04837b078afeb5a0351cbac4f SHA-1: 7685120e594310d2371ffcc43c659ed821e7780c SHA-256: 8cc18159f631fcb4cd2ba9a4f5e17026e5dbdaa282b016bd1cd42434f85bc5ee
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, likely serving as a distribution point for phishing or further malware. The PDF's structure and embedded links suggest it is part of a larger malicious campaign, potentially using spearphishing attachments as an initial vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609c567170f42---84931128046.pdf
    • https://music-group-store.com/upload/files/jurejenofibupanipu.pdf
    • https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/2lpigq311q98q9ld39u7176306/kagavegovusibi.pdf
    • https://xn----9sbccjdbca7cyaieg1a3j.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/d1bc6538a190ee9aeca3d3d3edcae199/vurijezafufikudum.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/4senji2jl2f6mk56ml0pr0rm5l/zopoxofatavewewu.pdf
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6710672596---70728782666.pdf
    • https://italvaping.com/file/5736058930.pdf
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076a4d537951---dunopifudezarutavu.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb713f49a1e---xavelokogu.pdf
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607556f199dd0---1436383247.pdf
    • http://bjbtrh.com/files/pic/file/43967019529.pdf
    • http://xlsferrosilicon.com/d/files/gilikevozojenejobiwaw.pdf
    • https://wkd-uk.com/wp-content/plugins/super-forms/uploads/php/files/4e15ff29bc4be39343e5b9df0cfc6663/jelawiwox.pdf
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c637aed4d1---82726655788.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a40aa5893d---dajinadurosivusazuroka.pdf
    • http://trungtinjsc.vn/upload/FCK/file/raxibidubugiwowaxuxejosa.pdf
    • http://gapoom.com/upload/fckeditor/file/16774696606.pdf
    • http://the-bom.kr/upfile/files/92212600672.pdf
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/cb1608a0c2155d08ccecade6310122c2/xipanatisopifozufudive.pdf
    • http://re-view.online/fckFiles/file/xanejuzomidozo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=diagn%C3%B3stico+cl%C3%ADnico+y+tratamiento+2020+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_off0000f659.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF659 16792 bytes
font_01_sfnt_off00010e70.bin
7ce8c181c284f8e8a0572c3a7759e09c792b37cd56c96bdd2055bc5d3a2cddc2
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E70 11520 bytes
font_02_sfnt_off00012948.bin
e13fa380a09049a759f6271c81a3fbbd648800afa4a7378eb3ae7b3e5fb58773
pdf-font-stream PDF embedded font (sfnt) at offset 0x12948 17564 bytes