Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac35a88b4cda4532…

MALICIOUS

PDF

90.7 KB Created: 2021-08-29 07:36:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6336a6848048f3c5e9e9ce7b1ac8e804 SHA-1: 6b34cc40b1a88dff7b0ee1aa95e6603b73bb30ff SHA-256: ac35a88b4cda4532e4d749ef45d4b3cdd7c1cc2ba7419c2001ed5aab0e146a40
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The presence of numerous URLs pointing to compromised CMS upload directories and disposable hosting suggests a link farm designed to obscure the ultimate destination, likely a phishing page or malware download. Although no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16083affd34491---90326684647.pdf
    • http://ecohost.ru/pics/images/file/57343552445.pdf
    • http://ackerviewguesthouse.com/userfiles/file/vosijajarubafolivoluf.pdf
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/3c483ae2c878ed7f1dc6bb43396a9826/20924100751.pdf
    • https://ndmoyun.com/calisma2/files/uploads/99569423445.pdf
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/l5eqa0fn3cgj1cb60fi5usbda7/49421087381.pdf
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/a8ccb355429909096d313ca362c3ea18/62830662417.pdf
    • https://connect.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/740ef1421dd84385c6729f327e2d9e22/tagixut.pdf
    • http://ave-france.com/pics/files/67681820008.pdf
    • http://bjaimama.com/data/upload/2021/05/file/202105192319511949.pdf
    • http://plusbateria.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2b2c0535d2---zelirewimeposo.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/a9c705415432b37363e1c3ae3a30abcb/15795516679.pdf
    • http://maility.pl/_ADRESuserfiles/file/45777291547.pdf
    • http://grafosaleservice.cz/images/fck_editor/file/wuburojojareloximupu.pdf
    • http://bascobrunswick.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160833ca75bfac---wufukobofujudiwej.pdf
    • http://sbsinternationalschool.org/sbsisnew/userfiles/file/sirovivofomuwolavap.pdf
    • http://ebsenglish.net/_UploadFile/Images/file/buxakepalakuduk.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160fa4bf6bd53d---xanaxikuxuw.pdf
    • http://ilovechardonnayhills.com/userimages/64193430283.pdf
    • http://broadgatecapital.com/userfiles/file/giwudatojunefinutu.pdf
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607424497fa01---donedibatomafawu.pdf
    • http://sanruou.com/app/webroot/uploads/files/29029624053.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c2b4deb0cfb---11312398984.pdf
    • https://global-product.org/CKEdit/upload/files/dojakegi.pdf
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/0d5rhc3e8iv3np1grerkb2pd5e/balitamaviwiwifixulatop.pdf
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/u5ral1fd2fpbb26tbj9j30l658/gusopifemexorowesanoturuj.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=the+forward+biased+characteristics+of+a+zener+diode+are+the+same+as+those+of+a+diode
    • 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_off0000fc8d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFC8D 16792 bytes
font_01_sfnt_off0001149f.bin
c44be81b40b4532efa0994f73f836b07ae0f01c9400484651ab0e0e7ab6d87f4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1149F 17528 bytes
font_02_sfnt_off0001428d.bin
19f11adbc6c3d634d499ef1daa3b15cd5f2df8ba2c5a15771e4a05ba0504f0ee
pdf-font-stream PDF embedded font (sfnt) at offset 0x1428D 10944 bytes