Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac6f5dc32cc35a2f…

MALICIOUS

PDF

70.0 KB Created: 2021-09-27 02:49:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a3158bcd053b65af397c84e7e4a64531 SHA-1: cdf8d1eacac88139ce9d56e02016f3624e84f155 SHA-256: ac6f5dc32cc35a2f9a2d67542a9771ff15519c1c058bfe7e371d0f0a1dd569cf
156 Risk Score

Malware Insights

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

The PDF contains a significant number of links pointing to external PDF files, many hosted on domains flagged as disposable or potentially compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure itself is designed to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://ku4ysk-9lgp4y.com/contents/files/kopomisalupazatavuk.pdf
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e52830dfef1aa2f758fd63001685075f/jubugukuzezen.pdf
    • http://jtylek.pl/Upload/file/rexab.pdf
    • https://thietbivesinhsonhoa.com/webroot/img/files/zoxudifibivire.pdf
    • http://henca.com/files/details/file/fizezizedikunudejuw.pdf
    • https://dom4m.by/userfiles/files/63835566761.pdf
    • http://xhiehchin.com/Xhieh_News/_file/lunajiwixoxeweredubujeze.pdf
    • http://orderkiwicafe.com/uploads/files/22257310457.pdf
    • https://genia-groupe.fr/images/files/taxapudipegunuwapifa.pdf
    • http://www.dreamstoreonline.es/ckfinder/userfiles/files/77971653061.pdf
    • http://excellent-art.com/userfiles/mabeput.pdf
    • http://yachtales.net/admin/userfiles/files/36784561041.pdf
    • https://keralatemples.info/ckfinder/userfiles/files/95139099932.pdf
    • http://capriololaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/29882388507.pdf
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/sr4soum7iqafrit7krmec09n2g/99373891313.pdf
    • http://lindendirect.com/ckfinder/userfiles/files/22160105543.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16131d301b73da---72783547211.pdf
    • https://pollackmihalyiskola.hu/ckfinder/userfiles/files/96694476799.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16150d197f09fb---79917870050.pdf
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/3vvjp2lbubiiulomsc6qv8lhi5/56823379207.pdf
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/tr094mds4qvm5g1m1tlplmg0c1/legudewekove.pdf
    • http://www.singchai.co.th/ckfinder/userfiles/files/kobefusigowasotu.pdf
    • http://knuhpharm.kr/userfiles/file/20210912035554.pdf
    • http://sva-jeanroze.com/xmedia/file/46693536601.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=catchers+game+hack
    • 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_off0000b131.bin
689e0c9d72181253964cfeff3dffd7d5955469a00283984b433f3d768e42ac5b
pdf-font-stream PDF embedded font (sfnt) at offset 0xB131 16500 bytes
font_01_sfnt_off0000db0f.bin
6d39270b66d9ea49964384a25fdd3d9c5179768c0ecb972bf3cb9c5937d468d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB0F 10436 bytes
font_02_sfnt_off0000f2d7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D7 16792 bytes