Malicious PDF — malware analysis report

Static analysis result for SHA-256 a43ad1814a91e53b…

MALICIOUS

PDF

86.0 KB Created: 2021-09-22 09:14:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b61a739be252ad618aaf469a2df122b4 SHA-1: 0f12fc2e119c3eae9b3d6c4b26693d007204c55e SHA-256: a43ad1814a91e53bfe64d3991f5ffa9461bdc62011b90e2d6c62f19ad56ed7ab
204 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including links to algorithmically generated URLs and compromised WordPress uploads. The presence of a 'download button' lure suggests an attempt to trick the user into downloading a secondary payload. The ClamAV detection and ML classifier further confirm its malicious nature, pointing towards a phishing or trojan distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://medvor.ru/uplcv?utm_term=battleheart+legacy+mod
    • http://lucidareemantenerepavimentifaidate.it/userfiles/files/21584323797.pdf
    • http://ramenzoni.eu/userfiles/files/lozakisobunumibe.pdf
    • http://ceramkgres.ru/userfiles/file/51932907013.pdf
    • http://www.zywawiara.pl/pliki/39044968014.pdf
    • http://kalikraft.com/images/file/25633748164.pdf
    • https://wendi101.com/userfiles/file/60225756111.pdf
    • http://hotelalbicia.com/userfiles/file/12468065378.pdf
    • http://marketingnews.fr/images/file/33420624194.pdf
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/dc38c0b42b546ffb25c52cf59a5ce39f/60214815053.pdf
    • https://hobbes-group.com/upload/files/35102485553.pdf
    • http://www.sictombbi.fr/ckfinder/userfiles/files/41836604009.pdf
    • http://lindendirect.com/ckfinder/userfiles/files/labogirosa.pdf
    • http://inica.org/files/file///bivoterufulezi.pdf
    • http://inimtrento.it/userfiles/files/sadipemenuta.pdf
    • http://www.findvoters.com/userfiles/file/zezuwurovisasawele.pdf
    • http://urotunisia.com/uploads/FCK_files/file/93927839104.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16146f03f7f9bf---vosumolir.pdf
    • http://sportgalaktik.sk/userfiles/file/worovivoselagidewifebu.pdf
    • http://freehajjandumrah.com/admin/admin/uploadfiles/file/gadiz.pdf
    • https://bykevin.com/wp-content/plugins/super-forms/uploads/php/files/b043c5e01d77389298f93213de721c38/dalagademizajowil.pdf
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161402befc6fd7---53532896702.pdf
    • https://arabadvertise.com/userfiles/files/didulijuxidejosavolulit.pdf
    • http://intelekt.biz/uploads/pages/files/runonijosuzijev.pdf
    • https://mimpiindah88.com/contents/files/lujikuvejeditob.pdf
    • http://nicolalazzarotto.com/userfiles/files/kozufesiz.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_off0000e81f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE81F 16792 bytes
font_01_sfnt_off00010031.bin
cabd3cd5fd9a9a0aaf9c927fe779e8dfbe812586c7239511a6fdf8c70b9c5e8d
pdf-font-stream PDF embedded font (sfnt) at offset 0x10031 19216 bytes
font_02_sfnt_off00013207.bin
717daaa707caa5fd521c192c3a6de555602384e5f63612c102c2c800c17ec26e
pdf-font-stream PDF embedded font (sfnt) at offset 0x13207 10620 bytes