Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfa512b03b91c816…

MALICIOUS

PDF

69.0 KB Created: 2021-09-11 12:23:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 681c5bab8573f3f5f7abcc6a4454a36e SHA-1: 45049bf62091868d57f24dd37f0110ae0224fff9 SHA-256: dfa512b03b91c816f2be48f2feafa48f43a06674d48d996d6f3925dc045844b2
174 Risk Score

Malware Insights

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

The PDF contains multiple heuristic firings indicating malicious intent, including random URL links and a link farm on disposable hosting. ClamAV detection and ML classification strongly suggest this is a malicious PDF, likely a phishing or trojan delivery mechanism. The presence of a 'download button' lure further supports a social engineering attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 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.
  • 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://allytemp.ru/uplcv?utm_term=android+10+ui+kit
    • https://dwitunggaljaya.com/sitefiles/file/51029765705.pdf
    • http://propack-th.com/image/upload/File/39646119297.pdf
    • http://ville-dammarie.com/ckfinder/userfiles/files/70625482016.pdf
    • http://assessmentinsight.com/ckfinder/userfiles/files/risunawekiwavejakamenager.pdf
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137803004067---16991039476.pdf
    • http://gzhangqin.com/uploadfile/files/46471340047.pdf
    • http://ckrestaurantgroup.com/ckfinder/userfiles/files/rofufasuxa.pdf
    • http://ssss-sangam.com/userfiles/file/50763687579.pdf
    • http://anapro.com/ckfinder/userfiles/files/31323014983.pdf
    • http://studioghittigargnano.com/userfiles/files/40223799443.pdf
    • http://www.teeintact.com/admin/fckeditor/editor/filemanager/connectors/php/img/file/pexukato.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16136af7ce4011---fabutubizadonarolo.pdf
    • http://donghotam.com/luutru/files/239139329.pdf
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/63752413768.pdf
    • http://thebrownbag.vn/upload/files/kozudisalilumadowa.pdf
    • http://mamadona.ru/ckfinder/userfiles/files/jofij.pdf
    • https://angelsolutions.ro/ckeditor/ckfinder/userfiles/files/22649891236.pdf
    • http://sambometal.com/dataroom/file/81374551144.pdf
    • https://suruburi.net/mm/file/20274682655.pdf
    • http://1yunnan.com/ckfinder/userfiles/files/lilupewupopipove.pdf
    • http://enidental.com/userfiles/file/20210907065103.pdf
    • http://canoto.us/Images_upload/files/19881417859.pdf
    • https://dunaweb.co/bg_image/files/kabinebexexatosapuminefen.pdf
    • http://studiocariola.com/userfiles/files/23521643146.pdf
    • http://pamatudarbai.lt/ckfinder/userfiles/files/jukalusojapinobejawubi.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_off0000b270.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB270 16792 bytes
font_01_sfnt_off0000ca82.bin
a101bc9d922994f1cae16266e20c8f6aa05dd62b89643426f48080b9355c17ae
pdf-font-stream PDF embedded font (sfnt) at offset 0xCA82 14900 bytes
font_02_sfnt_off0000f054.bin
f6b979de12bf36a96968538e4509eef2ac91483d34fccc4dbb4435c8ef9a457c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF054 10080 bytes