Malicious PDF — malware analysis report

Static analysis result for SHA-256 876a85462d7f8dce…

MALICIOUS

PDF

91.1 KB Created: 2021-07-14 01:04:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fb533daec0982782f63478705c5ec48a SHA-1: b60969dec9624effa37a33c1761a8c1a3d0575f5 SHA-256: 876a85462d7f8dceb89eaeb749aa03cb4902202ce0a4b70286e3ff1c9a9bdae5
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains a large number of links, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm used for SEO manipulation or to host malicious files. The presence of external URIs and the overall structure indicate an attempt to redirect the user to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

Heuristics 6

  • 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.
  • 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 http://middlegeorgiacoinclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607650385d136---58314401573.pdf
    • http://merklink.nl/site/data/ws/files/duwefimobuv.pdf
    • https://dgaspcsm.ro/ckfinder/userfiles/files/wonogakuvavawuzadewukimu.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4f83464f83---85071971116.pdf
    • http://antifftech.com/uploadfile/file///2021051022313114.pdf
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160d5fd09ac1dc---dogukakebomilewolumolat.pdf
    • http://ahchala.com/img/file/mixutinimonajelev.pdf
    • http://aqbnb.com/uploadfile/file/wumimuletimo.pdf
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/8ef5c1b6b97e881ee936432944231943/99939729748.pdf
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/78ec21484c3638bc602b08d88080ba90/kimevipexuvokib.pdf
    • https://ludifrance.fr/userfiles/file/turuwewudixazopafokepuw.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f1f3272767---77910376905.pdf
    • https://asthasupermarket.com/userfiles/file/gobelosexudopububewow.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/1b7c4ee20727b2c390adfff3371b5d4b/tuvimoluxedemezavipo.pdf
    • http://thedewakohchang.com/image/upload/File/7558768123.pdf
    • https://etcbt.com/userfiles/file/mabumijedo.pdf
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/10b03203e682788c18d2074c1af91ed3/35146301083.pdf
    • http://assushop.com/userfiles/assushop.com/file/30367807250.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/4levs5e8nk1iglikahaum5m93m/67959323509.pdf
    • https://nguyenhungstone.com/uploads/image/files/vekewigavoxaviwonu.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16087e353dc15e---62414703823.pdf
    • http://shsuorui.com/uploadfiles/fckeditor/20210708/file/16257468025042.pdf
    • http://frangarcia.eu/upload/file/78896697468.pdf
    • https://etonbio.com/newsLetters/images/file/70479605071.pdf
    • http://washburnhs64.com/clients/f/f7/f75dc469904bb25755ea64d7551c4a95/File/46685155374.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=the+new+australian+and+new+zealand+public+relations+manual
    • 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_off0000ff67.bin
82c91c52ceedbfb4645eae57602cd400fafff9a101db5753bfbe4baa77c45cfd
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF67 17600 bytes
font_01_sfnt_off00012cc1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12CC1 16792 bytes
font_02_sfnt_off000144d8.bin
cbfac0480d982a3f47b7b4a5d6b15b5e7faebf0e16d102d588959e36157c033e
pdf-font-stream PDF embedded font (sfnt) at offset 0x144D8 11128 bytes