Malicious PDF — malware analysis report

Static analysis result for SHA-256 77ef87c40242cc61…

MALICIOUS

PDF

86.8 KB Created: 2021-06-27 22:33:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2082b3a605d6bb0a267c7ec05d359d52 SHA-1: 5a1918d4243723d63b73ee8546df84978a843561 SHA-256: 77ef87c40242cc61f5840985c4eab3ff2eba21ef7872a9639933c5bd6420ba86
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of multiple links on disposable hosting and compromised CMS uploads reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://ecohost.ru/pics/images/file/85164459708.pdf
    • http://naucseto.cz/storage/nilelatiteki.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/km3iuqega3eaefmo13am6ba0t5/wirovogowonanokubojidag.pdf
    • https://mujeresenmovimientoplus.com/userfiles/file/gupejo.pdf
    • https://bcbc3399.com/upload/files/vamisekonoxizusofa.pdf
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9dcb072020---85077094752.pdf
    • https://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/op6nra5uv6jj7mjsiulvlih42r/50211083138.pdf
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b84cbd6d83d---posonamamula.pdf
    • http://christopherdallo.com/file/bulitanezosajize.pdf
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/552158f7e97e6ffc0c418c1355db1cdf/zupatapanodajosarigizos.pdf
    • https://hohsingfiber.com/ufiles/files/jamubufuroxonudikoxaku.pdf
    • https://www.breastcancerfoundation.in/wp-content/plugins/super-forms/uploads/php/files/b6b7bf986ce7ba0a924117e185c89c66/jivapo.pdf
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c8b1a5ea061---41586262555.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160857b8b4c754---lifid.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098b2048a5c1---jogadifupevefidalawifuxa.pdf
    • https://rubyyadav.com/nbloom/fckuploads/file/27487374179.pdf
    • https://cuisinescartier.ca/upload/editor/file/vezatexovivegudigurej.pdf
    • https://centar-znr-zop.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160bcb66ef2116---fesov.pdf
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/25pdsiugg9ckbdafrssbuhpcs7/49480374470.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/5496ef43fcb0be1bdcf8198e5ff39a53/90604427548.pdf
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/f93e799768c87a38d2a9b8ac66be6de6/sikesopaxumimotabaxokimos.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb8cb1f65d---19476784446.pdf
    • https://hpx.com.ua/wp-content/plugins/super-forms/uploads/php/files/57beb7742c4cd0cddb45624ff70f5cd8/demado.pdf
    • https://thaiahpa.com/flash/files/926491683.pdf
    • http://accomplishtheimpossible.com/userfiles_ati/file/26283268318.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=math+problems+for+5th+graders
    • 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_off0000ed5f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED5F 16792 bytes
font_01_sfnt_off00010571.bin
16eb97846e23b2bfc877b2623acd553ec6d479eb79dcb9afb917bd4f6d4e02c9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10571 17380 bytes
font_02_sfnt_off0001333c.bin
c46a80f89007849423937cf28852dc58ff929b5b206f07b3bf9de3ae3895989e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1333C 11016 bytes