Malicious PDF — malware analysis report

Static analysis result for SHA-256 985cb93d15a1cefe…

MALICIOUS

PDF

87.9 KB Created: 2021-07-04 12:37:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 64f67d48da731af365d762d3f4299adf SHA-1: b0491009a9f6fe82b26810c12ef9b5a0428e6f5e SHA-256: 985cb93d15a1cefeddde5c1eaf3fa7013f4337ccb30a71119835414af544406a
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised WordPress sites that host further PDF files. These secondary PDFs are likely designed to lure users into phishing scams or download additional malware, making the initial PDF a component of a multi-stage attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d353488b9---34749358766.pdf
    • https://spectrumohio.com/wp-content/plugins/super-forms/uploads/php/files/819cc2650c4e4e31e0dd39bca24abb89/38714804665.pdf
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/f5oib0ne6rv9a063b69na2nj39/9589282861.pdf
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/330dcc3f807657a972d56a565856886b/jogaxelazorojit.pdf
    • https://pavaniautismschools.com/wp-content/plugins/super-forms/uploads/php/files/ad0tima7u8vucidpgh7k6pu3ip/91494275278.pdf
    • https://cgeminfos.ma/upload/file/12163143088.pdf
    • http://wjvanderheidedienstverlening.nl/uploads/file/wevawagamijovigisug.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/fd76591bb0b2be96b0832bc9add5ca87/dabivomazomewemasurigu.pdf
    • http://popnmusic.fr/userfiles/file/87199158986.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a182994b8d7---luzakevimefazipo.pdf
    • http://schokobrunnen.com/idata/rimefokiwikoxamag.pdf
    • https://clubslotalmatriche.com/calcas/file/86034815435.pdf
    • https://elitstroycraft.ru/source/file/pakujaxubuzizinav.pdf
    • http://jucal.es/images/file/votul.pdf
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c780d5312b---52215388459.pdf
    • https://bbmint.com/userfiles/file/99180180702.pdf
    • http://studionegro.net/userfiles/files/92548083442.pdf
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/b4e6cca2e699b7c6ce03c79319f0de76/nizudedowunijamejobesobav.pdf
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a543d5d6f9f---52045605207.pdf
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609c087a70ac7---96099125701.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=addition+of+similar+fractions
    • 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_off0000f255.bin
5038101ab258ecea74ad8036af43f407cb0cebdcd74d484e01435ee4ccbf2a9a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF255 10484 bytes
font_01_sfnt_off00010a28.bin
6cabbb84312b470dc00d9baa1c1a9beab9821bf138d9d3138bf8d97f3f14af5d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A28 17724 bytes
font_02_sfnt_off000138bb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x138BB 16792 bytes