Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cdf61a54c60e6cc…

MALICIOUS

PDF

85.0 KB Created: 2021-09-12 13:25:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b44824383e91de560006ae873a7f96c3 SHA-1: 806476347085e68c7e8c2dfac94bfb901c1da490 SHA-256: 1cdf61a54c60e6ccceeb9ccb0b8e15a542576a06c0c321e8623a7e92025ff435
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://krisoc.ru/uplcv?utm_term=gangstar+vegas+for+windows+7
    • http://www.pranabkumar.com/fckimages/file/demesizexeweluk.pdf
    • http://gdlianyu.com/uploadfiles/file/64557174623.pdf
    • http://kowel.com/ckfinder/userfiles/files/1631319121.pdf
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/161354e80374e3---juvawumimexipakalijep.pdf
    • https://svltv.in/userfiles/files/73990577732.pdf
    • https://www.tonygssoulfood.com/wp-content/plugins/super-forms/uploads/php/files/a6e6300325225a1bf6fdfbb85f19b07c/rejuto.pdf
    • http://groupelamiri.com/uploads/FCK_files/file/42453375762.pdf
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613460709ff91---84851937313.pdf
    • http://ipea.kr/userData/board/file/vazijexetudonisofarizaxol.pdf
    • http://studioghittigargnano.com/userfiles/files/mojorugoge.pdf
    • https://aokman-drive.com/d/files/fenin.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/1613a4605e7584---vajogujibedema.pdf
    • https://foundationkuzmanov.com/files/10109483682.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d5b85c0c61---malitusesepipogotine.pdf
    • https://namkhoasaigon.vn/web/images/files/93232580034.pdf
    • https://monyetjoget.com/contents/files/xakulirafalenovalulu.pdf
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613257afbf37b---lulakufiraretis.pdf
    • http://safetruck.gr/images/file/78993857668.pdf
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/943bf54dd87b6bd3d006dacd921a437c/83265545122.pdf
    • https://ppuhperspektywa.pl/files/edytor/file/ribezutolugoruxagenob.pdf
    • http://itexpertdog.nwoasis.com/upload/files/pixuzadexedujelojopi.pdf
    • http://dakmoto.cz/obrazky/file/43159800751.pdf
    • http://yishiweb.com/upfiles/files/20210907_213810.pdf
    • http://mobilni-kadernictvi.cz/files/file/79823987133.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_off0000e270.bin
042f1c76b262e961de9d8ddfad7eae950fad63572fba6d485380eaaee893f57e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE270 19520 bytes
font_01_sfnt_off00011587.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11587 16792 bytes
font_02_sfnt_off00012d9e.bin
d01e82178f951372e35cde29e4a0b78ac4c3f5425f63a9056550256cb3af1ba6
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D9E 10724 bytes