Malicious PDF — malware analysis report

Static analysis result for SHA-256 187fd28dcedc2e62…

MALICIOUS

PDF

81.6 KB Created: 2021-09-11 17:47:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d9c7546e55020ec9a24087930b758ad2 SHA-1: b5731da53ab24d37c7ea6486f9ccdb08a04a18ca SHA-256: 187fd28dcedc2e6225bf080178dda65ec83878b85a60d16b5cdcb35355cd862c
196 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, exhibiting characteristics of a phishing or trojan delivery mechanism. The 'SE_CLICKFIX' heuristic indicates the document employs social engineering to prompt the user to execute a command, likely to download and run a secondary payload. Numerous URLs were extracted, many pointing to PDF files hosted on compromised or disposable domains, suggesting a link farm or distribution network.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://pistant.ru/uplcv?utm_term=free+pdf+editor+software+for+windows+7
    • http://cn-biyoute.com/d/files/5229371635.pdf
    • https://srldirect.com/ckfinder/userfiles/files/zedovorob.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0c1b0f9c87c403089f1a5d1c4895741c/jozulov.pdf
    • https://onecre.com/images/content/files/dowosabareleluximifa.pdf
    • http://fuerst-architects.com/uploads/file/jagobeledonuvajos.pdf
    • http://hatdesechia.com/storage/ckfinder/files/wotimudizenijovede.pdf
    • https://vcubusinesssolutions.com/userfiles/file/35122373946.pdf
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/j3ittrsvg3h5a8fmk3blla26d7/90472809954.pdf
    • http://humanitool.ru/userfiles/file/48766819444.pdf
    • http://hoteldazegliotorino.com/userfiles/files/kediboziwudemediletorudoz.pdf
    • http://abwwilson.com/uploads/files/10285442234.pdf
    • http://metafelix.it/userfiles/files/vidanudekisonojek.pdf
    • http://forumts.com/ckfinder/userfiles/files/54826056784.pdf
    • http://archifolder.com/userfiles/files/46706190982.pdf
    • https://najlepsze-w-polsce.pl/uploads/rejazodebubuveberabuzivu.pdf
    • http://techbico.vn/uploads/image/files/29300031522.pdf
    • http://rococosofa.com/files/files/99199716319.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16131e241ad703---rumomudopimoda.pdf
    • http://www.texaco.bargiel.com.pl/ckfinder/userfiles/files/bawodokofagutipadu.pdf
    • https://doktor-ara.com/userfiles/files/zoresopin.pdf
    • http://metalltechnik-kutschi.at/zozikevukotovoma.pdf
    • http://www.jindatunnel.com/up_files/file/42776847028.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613be7e8af080---nodisenoziwugejagedede.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_off0000d976.bin
7ca724d6750ade1f9fc5893975edb2d5ac898ba420df7380560d6afb312e33a7
pdf-font-stream PDF embedded font (sfnt) at offset 0xD976 10560 bytes
font_01_sfnt_off0000f1c1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C1 16792 bytes
font_02_sfnt_off000109d3.bin
bc26f2f73750b7e2ffbd1112b3e521084fd166c04553ff246464fc1ae5313bb2
pdf-font-stream PDF embedded font (sfnt) at offset 0x109D3 18208 bytes