Malicious PDF — malware analysis report

Static analysis result for SHA-256 9939df71ac984318…

MALICIOUS

PDF

100.2 KB Created: 2021-06-25 14:14:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 76e78033942d3720978ccbf4b42521ba SHA-1: 443d089d4b97d9f54690b5443d64e034cc92303d SHA-256: 9939df71ac98431821c31abe19514ee1e0fee471508d2ed79516ece605181f4e
164 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised websites and disposable hosting domains, likely to facilitate the download of further malicious payloads. The presence of external URI heuristics and the 'compromised CMS upload link farm' finding strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://rsun.pro/admin/ckfinder/userfiles/files/lumogopomudifus.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099eefb3b612---jozupiman.pdf
    • https://mrmusicfoundation.org/wp-content/plugins/super-forms/uploads/php/files/s0o51ab8phoeask4il11lvvcrb/16581237388.pdf
    • http://inter-travel.hu/_user/file/vujigokadivaz.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b94d1127cb2---18055179021.pdf
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b7cad95729e---jalebokedazutez.pdf
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afd328caef5---3555136059.pdf
    • http://rszm88.com/upfolder/e/files/20210609150714.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aba0c8dbfa1---lupiramoragefov.pdf
    • https://mut-zur-veraenderung-hambuch.de/userfiles/file/69289578552.pdf
    • https://notofthisgalaxy.com/wp-content/plugins/super-forms/uploads/php/files/n1n79k7dq9tc40j2inn4ntjotq/jebenojugaw.pdf
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c27d54de364---begiw.pdf
    • http://angeladaniel.eu/uploads/files/ganib.pdf
    • http://alnoorcity.com/userfiles/file/ruseri.pdf
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160aebcc8e88da---33016595336.pdf
    • https://fotoprint.lv/downloads/file/71108701857.pdf
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160867b9caaea0---wigilup.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=paragraph+with+nouns+and+pronouns
    • 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_off00012344.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12344 16792 bytes
font_01_sfnt_off00013b5b.bin
df2c0c16d1eefdc786db577bc8beba24bbda02e8744b277263ad2e1943af80c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x13B5B 10680 bytes
font_02_sfnt_off0001539f.bin
cd3d311126a09c8190495bc880d1c5a138afe3349adc89ee628db084a63db195
pdf-font-stream PDF embedded font (sfnt) at offset 0x1539F 17944 bytes